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Accuracy The share of all cases a model gets right; simple to read, but it can look excellent when the thing you care about is rare.
Like a weather forecaster in the desert who says “no rain” every single day and is right almost every time, yet useless on the one day it pours.
https://cmaintz.github.io/tech-atlas/en/terms/ai/accuracy/ atlas ai evaluation atlas-en-ai/accuracy
Activation function The rule each unit in a neural network applies to its summed input, letting the network learn curved rather than straight patterns.
Like a dimmer switch that stays fully off until you turn it past a certain point, then lets more light through the further you turn. That bend is what lets many simple switches together make rich patterns of light.
https://cmaintz.github.io/tech-atlas/en/terms/ai/activation-function/ atlas ai ml-fundamentals atlas-en-ai/activation-function
Adversarial example An input altered on purpose, often in ways people cannot see, so that a trained AI model gives a confident but wrong answer.
Like an optical illusion made for a machine - a few dots a person would never notice make the computer see a cat as a toaster.
https://cmaintz.github.io/tech-atlas/en/terms/ai/adversarial-example/ atlas ai ai-risk atlas-en-ai/adversarial-example
Agent instructions file A plain text file kept with the code that tells AI tools the project's rules, commands and habits before they start work.
Like the folder kept aboard a sailing club's shared boat, which every member reads before taking her out - how to start the engine, where the key hangs, never moor by the rocks.
https://cmaintz.github.io/tech-atlas/en/terms/ai/agent-instructions-file/ atlas ai ai-coding atlas-en-ai/agent-instructions-file
Agent memory Notes an AI agent saves outside the model and reads back later, so it can carry facts and past work from one chat to the next.
Like a nurse's notebook passed between shifts - whoever starts work reads the notes first, because nobody remembers yesterday on their own.
https://cmaintz.github.io/tech-atlas/en/terms/ai/agent-memory/ atlas ai agents atlas-en-ai/agent-memory
Agent sandbox A walled-off space where an AI agent runs code and uses tools, so a mistake or trick cannot reach the rest of your systems.
Like letting a new cook practise in a test kitchen instead of the restaurant - if they set the pan on fire, only the test kitchen gets burnt.
https://cmaintz.github.io/tech-atlas/en/terms/ai/agent-sandbox/ atlas ai security agents atlas-en-ai/agent-sandbox
Agent2Agent protocol (A2A) An open standard that lets AI agents built by different companies find each other, hand over tasks and share results.
Like a shared job board for freelancers - each posts what they are good at, and others can hire them for a piece of work without caring how they do it.
https://cmaintz.github.io/tech-atlas/en/terms/ai/agent-to-agent-protocol/ atlas ai agents atlas-en-ai/agent-to-agent-protocol
Agentic workflow A fixed chain of steps written in code, where a language model does some of the steps but does not choose the order.
Like a relay race on a fixed route - each runner is fast and skilled, but where they run and whom they hand the baton to was settled before the start.
https://cmaintz.github.io/tech-atlas/en/terms/ai/agentic-workflow/ atlas ai agents atlas-en-ai/agentic-workflow
AI agent An AI system that does not just answer but acts - it plans steps and uses tools such as email, files or web search to reach a goal.
Like an assistant given your keys and a to-do list rather than a chat window - useful, but only as safe as the keys you hand over.
https://cmaintz.github.io/tech-atlas/en/terms/ai/ai-agent/ atlas ai llm atlas-en-ai/ai-agent
AI bias When an AI system treats some people or cases unfairly because of one-sided data or design choices.
Like a new manager who only ever learned from one old boss's hiring records - they copy every habit, fair or not, and do it at speed.
https://cmaintz.github.io/tech-atlas/en/terms/ai/ai-bias/ atlas ai ai-risk atlas-en-ai/ai-bias
AI code review Using a large language model to read proposed code changes and leave comments on bugs, risks and style before a person approves them.
Like a proof-reader who checks every letter before it is posted - quick to spot slips, sometimes fussy about nothing, and never the one who signs it.
https://cmaintz.github.io/tech-atlas/en/terms/ai/ai-code-review/ atlas ai ai-coding atlas-en-ai/ai-code-review
AI coding assistant A tool built into a programmer's editor that suggests, explains and rewrites code using a large language model.
Like a helper who has read a great deal looking over your shoulder while you write - quick with ideas and happy to explain, but it has not seen your whole project and is sometimes confidently wrong.
https://cmaintz.github.io/tech-atlas/en/terms/ai/ai-coding-assistant/ atlas ai ai-coding atlas-en-ai/ai-coding-assistant
AI governance The rules, roles and checks an organisation uses to decide which AI it uses and to keep that use safe, lawful and fair.
Like the house rules for a shared workshop - who may use which machines, who trains newcomers, who checks the safety guards, and who answers when something goes wrong.
https://cmaintz.github.io/tech-atlas/en/terms/ai/ai-governance/ atlas ai ai-risk atlas-en-ai/ai-governance
AI pair programming Writing code together with an AI tool in a running back-and-forth, where the human stays in charge and checks every change.
Like driving with a quick-thinking friend reading the map - they suggest turns and spot signs, but your hands stay on the wheel and you decide where to go.
https://cmaintz.github.io/tech-atlas/en/terms/ai/ai-pair-programming/ atlas ai ai-coding atlas-en-ai/ai-pair-programming
AI red teaming Testers attack an AI system on purpose, before and after release, to find ways it can be tricked into harmful or unsafe behaviour.
Like hiring clever troublemakers to spend a week trying to talk a new shop assistant into breaking every rule, so you learn where the training falls short before real customers do.
https://cmaintz.github.io/tech-atlas/en/terms/ai/ai-red-teaming/ atlas ai security ai-risk atlas-en-ai/ai-red-teaming
AI supply chain attack Attacking the ready-made parts an AI system is built from - shared models, datasets or plug-in files - instead of the system itself.
Like buying a spare part from a shop whose name differs by one letter from your usual one - it fits and works, but someone altered it before it reached you.
https://cmaintz.github.io/tech-atlas/en/terms/ai/ai-supply-chain-attack/ atlas ai security ai-risk atlas-en-ai/ai-supply-chain-attack
AI alignment The work of making an AI system aim for what people actually intend, and refuse what they would not accept.
Like King Midas, who wished that everything he touched would turn to gold and got exactly that - including his food. The wish was granted to the letter, not to the meaning.
https://cmaintz.github.io/tech-atlas/en/terms/ai/alignment/ atlas ai ai-risk atlas-en-ai/alignment
Artificial intelligence (AI) Computer systems that do tasks we normally link to human thinking, such as spotting patterns, answering questions or making choices.
An umbrella word, like “vehicle”, covering everything from a simple filter that sorts junk mail by fixed rules to a chat assistant that writes whole reports.
https://cmaintz.github.io/tech-atlas/en/terms/ai/artificial-intelligence/ atlas ai ml-fundamentals atlas-en-ai/artificial-intelligence
Attention mechanism The step inside a model that decides, for each token, which other tokens in the input matter most right now.
Like following one friend at a noisy party - out of all the voices in the room you pick up the few that matter to what you are hearing and let the rest fade.
https://cmaintz.github.io/tech-atlas/en/terms/ai/attention-mechanism/ atlas ai model-architecture atlas-en-ai/attention-mechanism
Backpropagation The bookkeeping method that works out, layer by layer from the output back, how much each weight in a network added to its mistake.
Like a kitchen following a burnt dish back through every cook who touched it, deciding how much blame each one carries, so each knows how much to change next time.
https://cmaintz.github.io/tech-atlas/en/terms/ai/backpropagation/ atlas ai training atlas-en-ai/backpropagation
Batch size How many examples a model looks at together before it updates itself once during model training.
Like a teacher marking homework; correcting after every single sheet is slow and jumpy, waiting for the whole class is steady but needs a big desk.
https://cmaintz.github.io/tech-atlas/en/terms/ai/batch-size/ atlas ai training atlas-en-ai/batch-size
Benchmark A shared, public set of tasks with a fixed way of scoring, so that different models can be compared on the same terms.
Like a standard fitness course that every athlete runs, with the same hurdles and the same stopwatch, so their times can be put side by side.
https://cmaintz.github.io/tech-atlas/en/terms/ai/benchmark/ atlas ai evaluation atlas-en-ai/benchmark
Bias-variance trade-off The tension between a model too simple to catch the real pattern and one so flexible that it chases chance details in its examples.
Like drawing a line through dots on a page. A ruler misses the curve that is really there, while a hand that passes through every single dot draws a wild shape that says little about where the next dot will land.
https://cmaintz.github.io/tech-atlas/en/terms/ai/bias-variance-tradeoff/ atlas ai ml-fundamentals atlas-en-ai/bias-variance-tradeoff
Chain-of-thought (CoT) Getting a language model to write out its steps before the final answer, which tends to help on sums, logic and planning.
Like a teacher who makes pupils show their working on a maths test - writing each step down makes fewer slips and lets you see where one went wrong.
https://cmaintz.github.io/tech-atlas/en/terms/ai/chain-of-thought/ atlas ai prompting atlas-en-ai/chain-of-thought
Chunking Cutting long documents into smaller passages before storing them, so a search can return just the part that answers a question.
Like cutting a long newspaper story into clippings for a folder - each clipping is quick to find, but cut in the wrong place and one clipping loses the ending.
https://cmaintz.github.io/tech-atlas/en/terms/ai/chunking/ atlas ai retrieval atlas-en-ai/chunking
Classification Teaching a computer to sort each new case into one of a fixed set of groups, such as approve or reject, or real attack or false alarm.
Like a coin-sorting machine at a bank; every coin drops into the slot for its value, and there is no slot for a coin it has never seen.
https://cmaintz.github.io/tech-atlas/en/terms/ai/classification/ atlas ai ml-fundamentals atlas-en-ai/classification
Clustering Letting a computer put similar items into groups by itself, with no names or right answers given in advance.
Like looking up at the night sky and seeing which stars sit close together; the groups come first, and the names for them come afterwards.
https://cmaintz.github.io/tech-atlas/en/terms/ai/clustering/ atlas ai ml-fundamentals atlas-en-ai/clustering
Code completion Greyed-out code that appears as you type, predicting the next line or block so you can accept it with one key.
Like a friend who finishes your sentences as you talk - nod and their ending is yours, or just keep talking and it is forgotten.
https://cmaintz.github.io/tech-atlas/en/terms/ai/code-completion/ atlas ai ai-coding atlas-en-ai/code-completion
Coding agent An AI that is given a programming task and carries it out itself - reading files, running commands and editing code until done.
Like leaving a carpenter alone in your house with a list of repairs - he gets on with it by himself, but he can also open any cupboard you left unlocked.
https://cmaintz.github.io/tech-atlas/en/terms/ai/coding-agent/ atlas ai ai-coding atlas-en-ai/coding-agent
Computer use Letting an AI agent work a computer like a person does - it looks at pictures of the screen and moves the mouse and types.
Like a stand-in sitting at your desk while you are away - they see the same screen, press the same buttons, and can do anything you could do from that chair.
https://cmaintz.github.io/tech-atlas/en/terms/ai/computer-use/ atlas ai agents atlas-en-ai/computer-use
Confusion matrix A small table that counts, for every true class, how often a model gave each answer, showing exactly which mistakes it makes.
Like a sorting office's end-of-day sheet showing how many letters for each town ended up in each town's bag, so you can see which towns keep getting mixed up.
https://cmaintz.github.io/tech-atlas/en/terms/ai/confusion-matrix/ atlas ai evaluation atlas-en-ai/confusion-matrix
Context engineering Choosing all a language model gets to see for a task - instructions, fetched documents, tool results, notes - not just the wording.
Like packing a small suitcase for a trip - what you leave out matters as much as what you put in, and what sits on top gets used first.
https://cmaintz.github.io/tech-atlas/en/terms/ai/context-engineering/ atlas ai prompting atlas-en-ai/context-engineering
Context window The most text, counted in tokens, that a language model can take in and keep in view at one time, including its own answer.
Like the size of a desk - everything the model is working on has to fit on it, and when it is full, something has to be cleared away to make room.
https://cmaintz.github.io/tech-atlas/en/terms/ai/context-window/ atlas ai llm atlas-en-ai/context-window
Convolutional neural network (CNN) A neural network built for pictures - it slides small pattern checks across an image to find edges, then shapes, then whole objects.
Like sweeping a small magnifying glass over a photo, first spotting lines, then eyes and noses, and finally saying “that is a face”.
https://cmaintz.github.io/tech-atlas/en/terms/ai/convolutional-neural-network/ atlas ai model-architecture atlas-en-ai/convolutional-neural-network
Cosine similarity A score from -1 to 1 for how closely two lists of numbers point the same way, used to tell how alike two embeddings are in meaning.
Like comparing two arrows by which way they point, not how long they are - two people walking north are going the same way even if one walks much further.
https://cmaintz.github.io/tech-atlas/en/terms/ai/cosine-similarity/ atlas ai retrieval atlas-en-ai/cosine-similarity
Cross-validation Checking a model fairly by splitting the examples into parts and letting each part in turn be the one held back for testing.
Like a teacher who splits a question bank into five piles and gives five mock exams, each time drawing on a pile the class did not practise, then takes the average mark.
https://cmaintz.github.io/tech-atlas/en/terms/ai/cross-validation/ atlas ai evaluation atlas-en-ai/cross-validation
Data drift The slow or sudden change in real-world data after a model goes live, so it no longer looks like what the model learned from.
Like an old city map that was right when it was printed, but the streets have been rebuilt since, so following it faithfully now gets you lost.
https://cmaintz.github.io/tech-atlas/en/terms/ai/data-drift/ atlas ai evaluation atlas-en-ai/data-drift
Data labeling Having people (or tools) attach the right answer to each example, such as “cat”, “complaint” or “angry”, so a model can learn from it.
Like writing the answer on the back of every flash card before a pupil starts practising with the deck.
https://cmaintz.github.io/tech-atlas/en/terms/ai/data-labeling/ atlas ai training atlas-en-ai/data-labeling
Data poisoning Slipping false or harmful examples into the data an AI learns from so that it later behaves the way an attacker wants.
Like secretly swapping a few pages in a student's textbook - they study hard, pass most tests, but give the wrong answer exactly where the pages were changed.
https://cmaintz.github.io/tech-atlas/en/terms/ai/data-poisoning/ atlas ai security ai-risk atlas-en-ai/data-poisoning
Decision tree A model that reaches an answer by asking a chain of yes or no questions about the input, each answer leading to the next question.
Like the game where you guess an animal by asking questions such as "Does it fly?" and "Is it bigger than a cat?", with each answer ruling out part of the list.
https://cmaintz.github.io/tech-atlas/en/terms/ai/decision-tree/ atlas ai ml-fundamentals atlas-en-ai/decision-tree
Decoder The half of a model that writes output one token at a time, each new token based only on what came before it.
Like a storyteller by a campfire who can hear everything said so far but never peeks ahead, adding one word, then the next.
https://cmaintz.github.io/tech-atlas/en/terms/ai/decoder/ atlas ai model-architecture atlas-en-ai/decoder
Deep learning Machine learning that uses neural networks with many stacked layers, the approach behind modern image, speech and language tools.
Like a line of workers where the first notices edges, the next shapes, the next faces, and each passes a richer picture up the line.
https://cmaintz.github.io/tech-atlas/en/terms/ai/deep-learning/ atlas ai ml-fundamentals atlas-en-ai/deep-learning
Deepfake A fake but convincing video, image or voice recording made with AI to show someone saying or doing what they never did.
Like a perfect mask and a perfect voice impression in one - except anyone with a laptop and a few minutes of someone's voice can now make one.
https://cmaintz.github.io/tech-atlas/en/terms/ai/deepfake/ atlas ai security ai-risk atlas-en-ai/deepfake
Diffusion model The kind of generative AI behind many image makers, which starts from random static and cleans it up step by step into a picture.
Like a sculptor who sees a figure in a rough block of stone and chips away a little at a time until only the figure is left.
https://cmaintz.github.io/tech-atlas/en/terms/ai/diffusion-model/ atlas ai model-architecture atlas-en-ai/diffusion-model
Dimensionality reduction Squeezing many inputs about each example into a few new ones that keep most of what tells the examples apart.
Like the shadow a hand throws on a wall, a flat outline of something solid, yet from the right angle you can still tell a dog from a bird.
https://cmaintz.github.io/tech-atlas/en/terms/ai/dimensionality-reduction/ atlas ai ml-fundamentals atlas-en-ai/dimensionality-reduction
Embedding A list of numbers that stands for the meaning of a piece of text, so that texts with similar meaning end up with similar numbers.
Like giving every text coordinates on a map of meaning - "car" and "vehicle" land near each other, "car" and "banana" far apart.
https://cmaintz.github.io/tech-atlas/en/terms/ai/embedding/ atlas ai llm atlas-en-ai/embedding
Embedding model A model that reads a piece of text and gives back an embedding instead of writing an answer.
Like a wine taster who marks every wine on the same flavour chart - light to heavy, sweet to dry - without ever telling you what the label says.
https://cmaintz.github.io/tech-atlas/en/terms/ai/embedding-model/ atlas ai retrieval atlas-en-ai/embedding-model
Encoder The half of a model that reads the whole input at once and turns it into embeddings that capture its meaning.
Like an interpreter who hears the whole sentence before saying anything, because a word at the very end can change what the first one meant.
https://cmaintz.github.io/tech-atlas/en/terms/ai/encoder/ atlas ai model-architecture atlas-en-ai/encoder
Epoch One complete pass of model training through every example in the training data; training often runs for several.
Like one full run-through of a choir's concert programme; a few run-throughs polish it, but after fifty the singers can only sing it exactly as rehearsed.
https://cmaintz.github.io/tech-atlas/en/terms/ai/epoch/ atlas ai training atlas-en-ai/epoch
EU AI Act The EU law that sorts AI systems by how much harm they could cause and sets stricter rules the higher the risk.
Like food safety rules that barely touch a bakery selling bread but put a baby-food factory under close inspection - the rules grow with what could go wrong.
https://cmaintz.github.io/tech-atlas/en/terms/ai/eu-ai-act/ atlas ai ai-risk atlas-en-ai/eu-ai-act
Excessive agency Giving an AI system more tools, rights or freedom to act than its job needs, so one wrong or tricked step can do real damage.
Like giving a new intern the master key, the company card and the power to sign contracts on day one, when all they were hired to do is sort the post.
https://cmaintz.github.io/tech-atlas/en/terms/ai/excessive-agency/ atlas ai security ai-risk atlas-en-ai/excessive-agency
Explainability How well people can understand why an AI system reached a particular result.
Like a doctor who does not just say "take these pills" but tells you what they saw in your tests and why that led to the choice.
https://cmaintz.github.io/tech-atlas/en/terms/ai/explainability/ atlas ai ai-risk atlas-en-ai/explainability
F1 score One number that blends precision and recall, so it stays low unless a model both finds the real cases and avoids wrong flags.
Like judging a goalkeeper on both saves and clean kicks, where being perfect at one and hopeless at the other still earns a poor mark.
https://cmaintz.github.io/tech-atlas/en/terms/ai/f1-score/ atlas ai evaluation atlas-en-ai/f1-score
Feature One measurable fact about an example, such as a price or an age, that a model reads as input when it makes a guess.
Like the boxes on a form, such as age, income and address, that a bank clerk reads before deciding on a loan.
https://cmaintz.github.io/tech-atlas/en/terms/ai/feature/ atlas ai ml-fundamentals atlas-en-ai/feature
Feature engineering Turning raw records into useful inputs for a model, by picking, cleaning, combining and reshaping the facts it will read.
Like a cook who washes, peels and chops the vegetables before cooking, because the same pot gives a far better dish when what goes in is well prepared.
https://cmaintz.github.io/tech-atlas/en/terms/ai/feature-engineering/ atlas ai ml-fundamentals atlas-en-ai/feature-engineering
Few-shot prompting Showing a language model a handful of worked examples inside the request, so it copies the pattern for the new case.
Like showing a new cashier three filled-in receipts before asking them to write the fourth - they copy the layout without a lesson.
https://cmaintz.github.io/tech-atlas/en/terms/ai/few-shot-prompting/ atlas ai prompting atlas-en-ai/few-shot-prompting
Fill-in-the-middle (FIM) A training trick that teaches a model to write the missing piece between the text before a gap and the text after it.
Like fitting the last piece of a jigsaw - the pieces on every side of the hole show its shape far better than looking at one side alone.
https://cmaintz.github.io/tech-atlas/en/terms/ai/fill-in-the-middle/ atlas ai ai-coding atlas-en-ai/fill-in-the-middle
Fine-tuning Giving an already trained model a short extra round of training on a smaller, focused set of examples to change how it behaves.
Like a trained nurse doing a short course to focus on children's care - the broad skills stay, a narrow set is sharpened.
https://cmaintz.github.io/tech-atlas/en/terms/ai/fine-tuning/ atlas ai llm atlas-en-ai/fine-tuning
Foundation model A large model built once on huge amounts of broad data and then reused as the starting point for many different tasks.
Like a general education that takes years to get, after which a person can learn to be a nurse, a lawyer or a cook in far less time.
https://cmaintz.github.io/tech-atlas/en/terms/ai/foundation-model/ atlas ai model-architecture atlas-en-ai/foundation-model
General-purpose AI model (GPAI) The EU AI Act's name for a broad model that can handle many different tasks and be built into many other AI products.
Like a company whose engine ends up in cars, boats and generators - the law asks the engine's maker for proper paperwork so every builder further down the line knows what they are fitting.
https://cmaintz.github.io/tech-atlas/en/terms/ai/general-purpose-ai-model/ atlas ai ai-risk atlas-en-ai/general-purpose-ai-model
Generative AI AI that creates new content (text, images, sound, code) in the style of the examples it learned from, instead of only sorting or scoring.
Like a street painter who has studied thousands of paintings and can paint you a new one in any style you name, though never one they saw exactly.
https://cmaintz.github.io/tech-atlas/en/terms/ai/generative-ai/ atlas ai ml-fundamentals atlas-en-ai/generative-ai
Graphics processing unit (GPU) A chip first built to draw screen images that does thousands of small sums at once, which is why it now runs most AI work.
Like a school hall of a thousand pupils each doing one easy sum at the same moment, instead of one professor working through the whole pile alone.
https://cmaintz.github.io/tech-atlas/en/terms/ai/gpu/ atlas ai ai-infrastructure atlas-en-ai/gpu
Gradient boosting A method that adds small decision trees one after another, each built to fix the mistakes the trees before it still make.
Like a team of editors passing a text along; the first fixes the worst errors, the next fixes what the first missed, and after many rounds very few errors are left.
https://cmaintz.github.io/tech-atlas/en/terms/ai/gradient-boosting/ atlas ai ml-fundamentals atlas-en-ai/gradient-boosting
Gradient descent The step-by-step method most models learn by, which nudges every setting a little in whichever direction makes the error shrink.
Like walking down a foggy hill with your eyes closed; you feel which way the ground slopes under your feet and take a small step downhill, again and again, until it is flat.
https://cmaintz.github.io/tech-atlas/en/terms/ai/gradient-descent/ atlas ai training atlas-en-ai/gradient-descent
Grounding Tying a model's answer to sources supplied with the question, so each claim can be traced back to a given document.
Like a student writing an essay where every claim must name the book and page it came from - if no book says it, it does not go in.
https://cmaintz.github.io/tech-atlas/en/terms/ai/grounding/ atlas ai retrieval atlas-en-ai/grounding
Guardrails Checks placed around an AI system that block unsafe requests going in and harmful or leaking answers coming out.
Like the barriers along a mountain road - they do not steer the car, but they stop it from going over the edge when the driver makes a mistake.
https://cmaintz.github.io/tech-atlas/en/terms/ai/guardrails/ atlas ai ai-risk atlas-en-ai/guardrails
Hallucination When an AI model states something false or made up - a fact, a quote, a source - in the same confident tone as a true answer.
Like a guest at a party who never admits not knowing - asked anything, they give a smooth, detailed answer, whether or not it is true.
https://cmaintz.github.io/tech-atlas/en/terms/ai/hallucination/ atlas ai llm atlas-en-ai/hallucination
Human-in-the-loop (HITL) Designing an AI system so a person must check or approve its work at key points before it takes effect.
Like a bank that needs a second signature for large payments - the clerk prepares everything, but the money only moves once a manager signs.
https://cmaintz.github.io/tech-atlas/en/terms/ai/human-in-the-loop/ atlas ai agents atlas-en-ai/human-in-the-loop
Hybrid search Running a word-matching search and a meaning-based search side by side and merging their results into one list.
Like asking both a strict clerk who only checks exact labels and a helpful friend who gets the gist - then trusting most what both of them point to.
https://cmaintz.github.io/tech-atlas/en/terms/ai/hybrid-search/ atlas ai retrieval atlas-en-ai/hybrid-search
Hyperparameter A setting a person chooses before model training starts, such as step size or number of rounds, and that the model does not learn itself.
Like the oven heat and baking time you set before the cake goes in; the cake does not choose them, but they decide how it turns out.
https://cmaintz.github.io/tech-atlas/en/terms/ai/hyperparameter/ atlas ai training atlas-en-ai/hyperparameter
Inference Using an already trained model to produce an answer for new input, which is what happens each time you ask a chat assistant something.
Like a trained doctor looking at a new patient; the years of study are over, and now the knowledge is simply being used.
https://cmaintz.github.io/tech-atlas/en/terms/ai/inference/ atlas ai ml-fundamentals atlas-en-ai/inference
Instruction tuning Extra training on many written requests paired with good answers, which turns a text-continuing base model into one that follows orders.
Like a well-read new employee who knows a lot but must be shown, through many worked examples, how the office expects a request to be handled.
https://cmaintz.github.io/tech-atlas/en/terms/ai/instruction-tuning/ atlas ai training atlas-en-ai/instruction-tuning
Jailbreak Talking an AI chat assistant out of its own safety rules with cleverly worded requests, such as role-play or made-up emergencies.
Like a child told “no sweets” who keeps trying new angles - “what if it's for my teddy?”, “Grandma always says yes” - until the tired parent gives in.
https://cmaintz.github.io/tech-atlas/en/terms/ai/jailbreak/ atlas ai security ai-risk atlas-en-ai/jailbreak
k-means clustering A method that splits data into a chosen number of groups by moving each group's centre until every point sits with its nearest centre.
Like placing three ice cream stands on a beach; each person walks to the closest stand, each stand then moves to the middle of its crowd, and you repeat until no one changes stand.
https://cmaintz.github.io/tech-atlas/en/terms/ai/k-means/ atlas ai ml-fundamentals atlas-en-ai/k-means
Keyword search Finding texts that contain the same words as the question, ranked by how often those words appear and how rare they are overall.
Like the index at the back of a book - look up "tax" and it lists every page where that exact word is printed, but not the page that says "duty".
https://cmaintz.github.io/tech-atlas/en/terms/ai/keyword-search/ atlas ai retrieval atlas-en-ai/keyword-search
Knowledge cutoff The date after which a language model saw no new text, so on its own it knows nothing about events that came later.
Like a printed travel guide - everything in it was true when it went to print, but it cannot tell you about the restaurant that opened last month.
https://cmaintz.github.io/tech-atlas/en/terms/ai/knowledge-cutoff/ atlas ai llm atlas-en-ai/knowledge-cutoff
Knowledge distillation Training a small “student” model to copy the answers of a large “teacher” model, so it keeps much of the skill at a fraction of the size.
Like a pupil who learns not only which answer the teacher picks but how sure the teacher is about each option, and ends up almost as good after far less study.
https://cmaintz.github.io/tech-atlas/en/terms/ai/knowledge-distillation/ atlas ai ai-infrastructure atlas-en-ai/knowledge-distillation
KV cache Memory where a language model keeps work it already did on earlier tokens, so each new word does not mean rereading everything.
Like keeping notes while reading a long book aloud - to say the next sentence you glance at your notes instead of starting again from page one.
https://cmaintz.github.io/tech-atlas/en/terms/ai/kv-cache/ atlas ai ai-infrastructure atlas-en-ai/kv-cache
Label The right answer attached to a training example, such as "spam" or a sale price, that a model learns to give on its own.
Like the answer key at the back of a school maths book, which lets a pupil check each sum and learn from the mistakes.
https://cmaintz.github.io/tech-atlas/en/terms/ai/label/ atlas ai ml-fundamentals atlas-en-ai/label
Large language model (LLM) A very large model trained on huge amounts of text to predict the next word, which lets it write, sum up and answer in fluent language.
Like the next-word suggestions on a phone keyboard, but trained on a large part of the internet - it knows how answers usually sound, not whether they are true.
https://cmaintz.github.io/tech-atlas/en/terms/ai/large-language-model/ atlas ai llm atlas-en-ai/large-language-model
Latency How long one request has to wait from being sent until its answer arrives - for an AI chat, the pause before and while it replies.
Like the wait between ordering a coffee and holding it in your hand - it says nothing about how many coffees the café makes in an hour.
https://cmaintz.github.io/tech-atlas/en/terms/ai/latency/ atlas ai cs ai-infrastructure atlas-en-ai/latency
Learning rate The setting that decides how big a step a model takes each time it adjusts itself to make fewer mistakes during learning.
Like walking down a foggy hill to reach the lowest point. Tiny steps get you there, but only after hours; giant leaps keep jumping past the bottom and may land you higher than where you started.
https://cmaintz.github.io/tech-atlas/en/terms/ai/learning-rate/ atlas ai training atlas-en-ai/learning-rate
Linear regression A simple model that predicts a number by adding up each input times its own weight, choosing the weights that fit past examples best.
Like guessing the price of a flat from its size by drawing the straight line that passes as close as possible to all the flats you already know the price of.
https://cmaintz.github.io/tech-atlas/en/terms/ai/linear-regression/ atlas ai ml-fundamentals atlas-en-ai/linear-regression
LLM-as-a-judge Using one large language model to grade the answers of another against a written scoring guide, instead of paying people to read them all.
Like a talent show where one seasoned judge scores every act from a printed sheet - quick and mostly fair, but the judge has favourites of their own.
https://cmaintz.github.io/tech-atlas/en/terms/ai/llm-as-a-judge/ atlas ai evaluation atlas-en-ai/llm-as-a-judge
Logistic regression A simple model that sorts cases into two groups by turning a weighted sum of the inputs into a chance between 0 and 1.
Like a doctor adding up points for age, smoking and blood pressure, then reading off a chart that turns the total score into a chance of illness that never goes below zero or above certain.
https://cmaintz.github.io/tech-atlas/en/terms/ai/logistic-regression/ atlas ai ml-fundamentals atlas-en-ai/logistic-regression
Low-rank adaptation (LoRA) A cheap way to fine-tune a big model - freeze the original weights and train only a small add-on that nudges its behaviour.
Like clipping a thin lens over a camera instead of rebuilding it - the camera stays the same, the pictures change, and you can swap lenses in seconds.
https://cmaintz.github.io/tech-atlas/en/terms/ai/lora/ atlas ai training atlas-en-ai/lora
Loss function The scoring rule that turns how wrong a model's answer is into a single number, which model training then tries to push down.
Like the penalty points in a driving test; each mistake adds points, and the learner practises until the total is as low as it can get.
https://cmaintz.github.io/tech-atlas/en/terms/ai/loss-function/ atlas ai training atlas-en-ai/loss-function
Machine learning Building computer systems that find patterns in examples and use them to make guesses, instead of following rules a person wrote.
Like learning to tell ripe from unripe fruit by handling thousands of pieces, rather than being handed a written list of rules.
https://cmaintz.github.io/tech-atlas/en/terms/ai/machine-learning/ atlas ai ml-fundamentals atlas-en-ai/machine-learning
MCP server A small program that offers tools or data to AI apps through the Model Context Protocol, such as reading mail or searching files.
Like letting a temp from an unknown agency into the office because their written list of skills looks useful - you only have their word for what they will actually do.
https://cmaintz.github.io/tech-atlas/en/terms/ai/mcp-server/ atlas ai agents atlas-en-ai/mcp-server
Mixture of experts (MoE) A way to build a very large model where only a few of its many parts do the work for each token, so answers cost far less.
Like a hospital full of specialists where the front desk sends each patient to the two doctors who fit best, instead of every doctor seeing every patient.
https://cmaintz.github.io/tech-atlas/en/terms/ai/mixture-of-experts/ atlas ai model-architecture atlas-en-ai/mixture-of-experts
Model card A short fact sheet that ships with an AI model and says what it is for, how it was tested and where it falls short.
Like the paper folded inside a box of medicine - what it treats, who should not take it, the known side effects and how it was tested.
https://cmaintz.github.io/tech-atlas/en/terms/ai/model-card/ atlas ai ai-risk atlas-en-ai/model-card
Model Context Protocol (MCP) An open standard for plugging tools and data into AI assistants, so each tool is hooked up once and works in many apps.
Like the standard wall plug - once every lamp and kettle uses the same shape, you can move any of them to any room without rewiring.
https://cmaintz.github.io/tech-atlas/en/terms/ai/model-context-protocol/ atlas ai agents atlas-en-ai/model-context-protocol
Model evaluation (evals) The practice of checking how well an AI system does its job, with scores, public tests, human review and deliberate attacks.
Like a car's road trials before sale, with speed runs on the track, crash checks, drivers' opinions and people trying hard to make it fail.
https://cmaintz.github.io/tech-atlas/en/terms/ai/model-evaluation/ atlas ai evaluation atlas-en-ai/model-evaluation
Model parameter One of the numbers inside a model that is set by learning from data; their count is how model size is usually stated.
Like the tiles in a huge mosaic; no single tile means much, but together their colours make the picture, and more tiles allow finer detail.
https://cmaintz.github.io/tech-atlas/en/terms/ai/model-parameter/ atlas ai training atlas-en-ai/model-parameter
Model serving Keeping a trained model running on machines so other programs can send it questions over an API and get answers back.
Like a power station - the design work is done; the daily job is keeping power flowing to every home, however many people switch on at the same moment.
https://cmaintz.github.io/tech-atlas/en/terms/ai/model-serving/ atlas ai ai-infrastructure atlas-en-ai/model-serving
Model training The costly, one-off stage where a model looks at training data again and again and tunes its internal numbers until its guesses improve.
Like a darts player throwing thousands of darts, checking how far each lands from the centre, and adjusting their arm a little each time.
https://cmaintz.github.io/tech-atlas/en/terms/ai/model-training/ atlas ai ml-fundamentals atlas-en-ai/model-training
Model weights The learned numbers that set how strongly each part of a neural network influences the next; in practice, the file that is the model.
Like the paths worn across a park lawn; every walk wears a route a little deeper, and together the worn paths decide where the next walker goes.
https://cmaintz.github.io/tech-atlas/en/terms/ai/model-weights/ atlas ai training atlas-en-ai/model-weights
Multi-agent system A setup where several AI agents share a job - often a lead agent splits the work and hands parts to helper agents.
Like a newsroom - an editor hands stories to several reporters at once, each digs into one angle, and the editor stitches their notes into one article.
https://cmaintz.github.io/tech-atlas/en/terms/ai/multi-agent-system/ atlas ai agents atlas-en-ai/multi-agent-system
Multimodal model A model that can take in, and sometimes produce, more than one kind of content - such as text, photos and speech - in one conversation.
Like a colleague you can hand a photo, play a voice message to and write to, all in one conversation - instead of three helpers who can each only read, look or listen.
https://cmaintz.github.io/tech-atlas/en/terms/ai/multimodal-model/ atlas ai model-architecture atlas-en-ai/multimodal-model
Nearest-neighbour search Finding the few stored items that sit closest to a given one, usually trading a little exactness for a lot of speed.
Like looking for the nearest open pharmacy - you do not measure the distance to every pharmacy in the country, you check the few in your part of town.
https://cmaintz.github.io/tech-atlas/en/terms/ai/nearest-neighbour-search/ atlas ai retrieval atlas-en-ai/nearest-neighbour-search
Neural network A model made of many small linked units that each weigh their inputs and pass a number on, loosely inspired by the brain.
Like a huge mixing desk with millions of sliders; training slowly nudges each slider until the sound that comes out is right.
https://cmaintz.github.io/tech-atlas/en/terms/ai/neural-network/ atlas ai ml-fundamentals atlas-en-ai/neural-network
Next-token prediction How a language model writes - it guesses the single most fitting next piece of text, adds it, and repeats until the answer is done.
Like finishing a well-known saying - hear “the early bird…” and “catches the worm” comes to mind - done over and over, one word at a time, until a whole answer stands.
https://cmaintz.github.io/tech-atlas/en/terms/ai/next-token-prediction/ atlas ai llm atlas-en-ai/next-token-prediction
Open-weight model A model whose learned numbers are published for anyone to download and run themselves, instead of only being reachable through an API.
Like buying a car you can keep in your own garage, service and modify, instead of only paying for rides - though the factory's drawings stay secret.
https://cmaintz.github.io/tech-atlas/en/terms/ai/open-weight-model/ atlas ai model-architecture atlas-en-ai/open-weight-model
Overfitting When a model learns its training examples by heart, including their noise, and then does badly on new cases it has not seen.
Like a student who learns last year's exam answers by heart, word for word, and then fails when the questions are slightly changed.
https://cmaintz.github.io/tech-atlas/en/terms/ai/overfitting/ atlas ai ml-fundamentals atlas-en-ai/overfitting
Precision Of all the cases a model flags as positive, the share that really are; in security terms, how many alerts were real.
Like a mushroom picker whose basket holds only good mushrooms; every one they chose was safe, even if they walked past plenty of others.
https://cmaintz.github.io/tech-atlas/en/terms/ai/precision/ atlas ai evaluation atlas-en-ai/precision
Pretraining The first, huge and costly stage of teaching a model, reading vast amounts of text to pick up general patterns before any special task.
Like a small child who hears years of everyday talk before starting school; nobody explains the grammar, yet the child picks up how the language works.
https://cmaintz.github.io/tech-atlas/en/terms/ai/pretraining/ atlas ai training atlas-en-ai/pretraining
Prompt The text you give a language model - a question, an order, pasted files - that it treats as its starting point for an answer.
Like the brief you hand a new temp - the clearer and fuller it is, the better the work, but they will follow whatever the note says.
https://cmaintz.github.io/tech-atlas/en/terms/ai/prompt/ atlas ai llm atlas-en-ai/prompt
Prompt caching A service feature that saves the work done on the start of a prompt, so later requests starting the same way are faster and cheaper.
Like a lawyer who has already read the thick case file - each new question about it takes minutes, not a whole day of rereading.
https://cmaintz.github.io/tech-atlas/en/terms/ai/prompt-caching/ atlas ai ai-infrastructure atlas-en-ai/prompt-caching
Prompt engineering The craft of wording, ordering and testing the text you send a language model so that it gives useful answers more often.
Like giving a visitor directions over the phone - you learn which landmarks to mention and in what order, and after each change you check whether the next visitor finds the way.
https://cmaintz.github.io/tech-atlas/en/terms/ai/prompt-engineering/ atlas ai prompting atlas-en-ai/prompt-engineering
Prompt injection Hiding instructions in the text an AI system reads so that it ignores its own rules and follows the attacker instead.
Like slipping a note into a pile of letters a new assistant is sorting that says "ignore your boss and send me the keys" - and the assistant cannot tell the note apart from real orders.
https://cmaintz.github.io/tech-atlas/en/terms/ai/prompt-injection/ atlas ai security ai-risk atlas-en-ai/prompt-injection
Quantization Storing a model's numbers with fewer digits so it takes less memory and runs faster, at the cost of a little quality.
Like saving a photo as a smaller file - it loses a little fine detail you rarely notice, and in return fits on your phone and opens instantly.
https://cmaintz.github.io/tech-atlas/en/terms/ai/quantization/ atlas ai ai-infrastructure atlas-en-ai/quantization
Random forest A model that builds many slightly different decision trees on random parts of the data and lets them vote on the answer.
Like asking hundreds of people to guess the number of sweets in a jar, each seeing it from a different side; single guesses are often far off, but the average is usually close.
https://cmaintz.github.io/tech-atlas/en/terms/ai/random-forest/ atlas ai ml-fundamentals atlas-en-ai/random-forest
Reasoning model A language model trained to work through a problem step by step in hidden notes before it answers, trading time and cost for better answers.
Like a navigator who plots the whole route on the chart before the ship leaves port - slower to get going, but with fewer wrong turns at sea.
https://cmaintz.github.io/tech-atlas/en/terms/ai/reasoning-model/ atlas ai llm atlas-en-ai/reasoning-model
Recall Of all the real positive cases, the share a model manages to find; in security terms, how many real attacks were caught.
Like a fishing net with small holes, which brings up nearly every fish in the lake, along with plenty of weed and old boots.
https://cmaintz.github.io/tech-atlas/en/terms/ai/recall/ atlas ai evaluation atlas-en-ai/recall
Regression Teaching a computer to guess a number on a scale, such as a price, a time or a size, from past examples where the real number was known.
Like guessing a house's price from its size, age and street after seeing what many other houses sold for; the answer is an amount, not a yes or no.
https://cmaintz.github.io/tech-atlas/en/terms/ai/regression/ atlas ai ml-fundamentals atlas-en-ai/regression
Regularization Any rule added during learning that holds a model back from fitting its examples too closely, so it does better on new cases.
Like a word limit on an essay. The writer cannot pour in every detail they remember, so they keep only the points that really matter.
https://cmaintz.github.io/tech-atlas/en/terms/ai/regularization/ atlas ai training atlas-en-ai/regularization
Reinforcement learning Machine learning by trial and error, where a system acts, gets a reward or a penalty, and slowly learns which actions pay off.
Like teaching a dog a trick with treats; nobody explains the trick, the dog just learns which moves earn a treat.
https://cmaintz.github.io/tech-atlas/en/terms/ai/reinforcement-learning/ atlas ai ml-fundamentals atlas-en-ai/reinforcement-learning
Reranking A second, more careful pass that reorders a first rough list of search results so the most useful ones end up on top.
Like a hiring manager who lets a quick sort pick fifty applications from a thousand, then reads those fifty properly before choosing five to interview.
https://cmaintz.github.io/tech-atlas/en/terms/ai/reranking/ atlas ai retrieval atlas-en-ai/reranking
Retrieval-augmented generation (RAG) Letting a language model first look up relevant passages in your own documents and then answer from them, instead of from memory alone.
Like an open-book exam - instead of answering from memory, the student first finds the right pages and then writes the answer.
https://cmaintz.github.io/tech-atlas/en/terms/ai/retrieval-augmented-generation/ atlas ai llm atlas-en-ai/retrieval-augmented-generation
Reinforcement learning from human feedback (RLHF) Improving a model by having people rank its answers, teaching a scorer from those rankings, then training the model to earn high scores.
Like a comedian trying jokes on a test audience, noting which ones get laughs, and gradually shaping the act around what the crowd prefers.
https://cmaintz.github.io/tech-atlas/en/terms/ai/rlhf/ atlas ai training atlas-en-ai/rlhf
Sampling How a language model picks each next piece of text from its list of likely options, by a set rule or with some chance involved.
Like choosing the next word in a story by drawing from a bag where common words have many slips and odd words have few - usually sensible, sometimes surprising.
https://cmaintz.github.io/tech-atlas/en/terms/ai/sampling/ atlas ai prompting atlas-en-ai/sampling
Self-supervised learning Machine learning where the right answers come from the data itself, for instance hiding a word in a sentence and guessing it back.
Like learning a song by pausing the recording mid-line, singing the next words yourself, then playing on to check. The song is its own answer key.
https://cmaintz.github.io/tech-atlas/en/terms/ai/self-supervised-learning/ atlas ai ml-fundamentals atlas-en-ai/self-supervised-learning
Semantic search Finding text by what it means rather than by the exact words it uses, so a question can match a passage phrased differently.
Like asking a friend who has seen every film for “that one where the big ship sinks” - they know what you mean even though you never said the title.
https://cmaintz.github.io/tech-atlas/en/terms/ai/semantic-search/ atlas ai retrieval atlas-en-ai/semantic-search
Sensitive information disclosure An AI system revealing private or secret details, such as personal data or business secrets, to someone who should not see them.
Like a chatty receptionist who has overheard everything in the office and, asked the right question in a friendly way, repeats a colleague's home address or salary to a stranger.
https://cmaintz.github.io/tech-atlas/en/terms/ai/sensitive-information-disclosure/ atlas ai security ai-risk atlas-en-ai/sensitive-information-disclosure
Shadow AI Staff using AI tools at work without the organisation knowing about them or having approved them.
Like an employee who takes work papers home to a friend for help - well meant, but the company has no idea who has read them or where copies ended up.
https://cmaintz.github.io/tech-atlas/en/terms/ai/shadow-ai/ atlas ai security ai-risk atlas-en-ai/shadow-ai
Slopsquatting An attack where criminals publish harmful packages under the made-up names that AI tools keep inventing for code.
Like a shop assistant who keeps recommending a brand that does not exist - until a crook notices, starts selling fakes under that exact name, and waits for customers to ask for it.
https://cmaintz.github.io/tech-atlas/en/terms/ai/slopsquatting/ atlas ai security ai-coding atlas-en-ai/slopsquatting
Small language model (SLM) A language model small enough to run cheaply on a laptop or phone, trading some broad skill for speed, privacy and low cost.
Like a pocket dictionary next to a full encyclopedia - it will not know everything, but it fits in your bag and answers the common questions right away.
https://cmaintz.github.io/tech-atlas/en/terms/ai/small-language-model/ atlas ai model-architecture atlas-en-ai/small-language-model
Spec-driven development Writing down exactly what the software must do, agreed by people, before letting AI tools write the code from that plan.
Like agreeing the menu and guest numbers with the cook before a wedding - the kitchen can then work fast, because nobody is guessing what to serve or for how many.
https://cmaintz.github.io/tech-atlas/en/terms/ai/spec-driven-development/ atlas ai ai-coding atlas-en-ai/spec-driven-development
Structured output Making a language model answer in a fixed, machine-readable shape - set fields in JSON - so other software can use the reply directly.
Like handing someone a paper form with labelled boxes instead of a blank sheet - whatever they write, it lands in the right box.
https://cmaintz.github.io/tech-atlas/en/terms/ai/structured-output/ atlas ai prompting atlas-en-ai/structured-output
Supervised learning Machine learning from examples that come with the right answer attached, such as emails already marked spam or not spam.
Like learning with an answer key. You try each exercise, check the key, and correct yourself.
https://cmaintz.github.io/tech-atlas/en/terms/ai/supervised-learning/ atlas ai ml-fundamentals atlas-en-ai/supervised-learning
Synthetic data Made-up examples produced by a program or another AI model to look like real records, used where real examples are scarce or private.
Like a flight simulator; the storms and engine failures are not real, but a pilot can practise them safely and as often as needed.
https://cmaintz.github.io/tech-atlas/en/terms/ai/synthetic-data/ atlas ai training atlas-en-ai/synthetic-data
System prompt Standing orders the maker of an AI service places ahead of every chat, setting the assistant's role, rules and tone before the user types.
Like a director's notes to an actor before the curtain rises - the audience never hears them, yet they shape every line, and a loud voice from the seats can still knock the actor off script.
https://cmaintz.github.io/tech-atlas/en/terms/ai/system-prompt/ atlas ai prompting atlas-en-ai/system-prompt
Temperature A per-request dial - low keeps a language model's wording steady and repeatable, high makes it more varied and less predictable.
Like a DJ's shuffle setting - turned down, you mostly hear the crowd favourites; turned up, more rare tracks slip in.
https://cmaintz.github.io/tech-atlas/en/terms/ai/temperature/ atlas ai prompting atlas-en-ai/temperature
Test set Examples locked away while a model is built and opened once at the end to give an honest final score.
Like the sealed envelope of exam questions that stays in the head teacher's safe until exam day, so nobody could have practised on them.
https://cmaintz.github.io/tech-atlas/en/terms/ai/test-set/ atlas ai evaluation atlas-en-ai/test-set
Throughput How much work a system gets through per second in total - for AI services, often counted as tokens or requests handled each second.
Like counting how many cars cross a bridge each hour - a wider bridge lets more through, even if each car drives no faster.
https://cmaintz.github.io/tech-atlas/en/terms/ai/throughput/ atlas ai cs ai-infrastructure atlas-en-ai/throughput
Time to first token (TTFT) How long a user waits after sending a prompt before the first piece of the answer appears on screen.
Like the pause after you ask someone a question and before they say their first word - a long pause feels slow even if they then talk quickly.
https://cmaintz.github.io/tech-atlas/en/terms/ai/time-to-first-token/ atlas ai ai-infrastructure atlas-en-ai/time-to-first-token
Token A small piece of text - a whole word, part of a word or a symbol - that a language model reads and writes in; also how use is priced.
Like Lego bricks for text - common words are one brick, rare or long words are built from several smaller bricks.
https://cmaintz.github.io/tech-atlas/en/terms/ai/token/ atlas ai llm atlas-en-ai/token
Tokenizer The part of a language model that cuts text into tokens and turns them into numbers on the way in, and back into text on the way out.
Like shorthand in a court reporter's notebook - a common word gets one quick mark, a rare word is spelled out in several, and the marks are turned back into words afterwards.
https://cmaintz.github.io/tech-atlas/en/terms/ai/tokenizer/ atlas ai llm atlas-en-ai/tokenizer
Tool calling How a language model asks outside code to do something for it - look something up, run a task - and then reads back the result.
Like a boss who cannot leave the office but can fill in order slips - each slip names a helper and says exactly what to fetch, and someone else walks it down the hall.
https://cmaintz.github.io/tech-atlas/en/terms/ai/tool-calling/ atlas ai agents atlas-en-ai/tool-calling
Top-p sampling A rule letting a language model pick only among its most likely next options, until their chances add up to a set share like 90%.
Like a quiz team that only considers answers they are fairly sure of - when one is obvious they go with it, when unsure they weigh several, and wild guesses never make the table.
https://cmaintz.github.io/tech-atlas/en/terms/ai/top-p-sampling/ atlas ai prompting atlas-en-ai/top-p-sampling
Tensor processing unit (TPU) Google's own chip made only for the number work inside neural networks, mostly rented out through Google Cloud rather than sold.
Like a machine at a brewery that only fills bottles - no use for anything else, but at that one job it beats a whole crew of all-round workers on a fraction of the power.
https://cmaintz.github.io/tech-atlas/en/terms/ai/tpu/ atlas ai ai-infrastructure atlas-en-ai/tpu
Training data The examples a model learns from; its behaviour, its blind spots and its mistakes all come from what is in them.
Like the textbooks and past exams a student studies from. If they are wrong, one-sided or out of date, so is what the student learns.
https://cmaintz.github.io/tech-atlas/en/terms/ai/training-data/ atlas ai ml-fundamentals atlas-en-ai/training-data
Transfer learning Reusing what a model already learned on one big task as the starting point for a new, related task, instead of starting from zero.
Like a car driver learning to drive a van; steering, traffic rules and road sense carry over, so only the size and the mirrors need practice.
https://cmaintz.github.io/tech-atlas/en/terms/ai/transfer-learning/ atlas ai ml-fundamentals atlas-en-ai/transfer-learning
Transformer The neural network design behind today's language models, which weighs how every word in a text relates to every other word.
Like reading a whole page at a glance and drawing lines between the words that belong together, instead of reading one word at a time.
https://cmaintz.github.io/tech-atlas/en/terms/ai/transformer/ atlas ai llm atlas-en-ai/transformer
Underfitting When a model is too simple or trained too little to catch the pattern, so it scores badly even on the examples it learned from.
Like describing every animal as “has legs”; the rule is too rough to tell a dog from a table, even for the animals you studied.
https://cmaintz.github.io/tech-atlas/en/terms/ai/underfitting/ atlas ai training atlas-en-ai/underfitting
Unsupervised learning Machine learning from examples with no answers attached, where the model finds groups, patterns or odd cases on its own.
Like sorting a box of mixed buttons into piles by colour and size without anyone telling you what the piles should be.
https://cmaintz.github.io/tech-atlas/en/terms/ai/unsupervised-learning/ atlas ai ml-fundamentals atlas-en-ai/unsupervised-learning
Validation set Examples held back from training and checked again and again while building a model, to choose its settings and decide when to stop.
Like a cook tasting the sauce again and again while it simmers, adjusting salt and time, which helps steer the cooking but is not the guests' honest verdict on the finished dish.
https://cmaintz.github.io/tech-atlas/en/terms/ai/validation-set/ atlas ai evaluation atlas-en-ai/validation-set
Vector database A store built to keep huge numbers of embeddings and quickly return the ones closest in meaning to a question.
Like a record shop that files albums by mood instead of by artist - ask for “something calm for a rainy Sunday” and the assistant walks you to one shelf.
https://cmaintz.github.io/tech-atlas/en/terms/ai/vector-database/ atlas ai retrieval atlas-en-ai/vector-database
Vibe coding Building software by describing what you want to an AI and accepting the code it writes without reading it.
Like having a builder put up a shed while you only glance at it from the kitchen window - if it looks fine and the door opens, you move in, never checking what holds up the roof.
https://cmaintz.github.io/tech-atlas/en/terms/ai/vibe-coding/ atlas ai ai-coding atlas-en-ai/vibe-coding
Zero-shot prompting Asking a language model to do a task from an instruction alone, with no worked examples to copy.
Like asking an experienced florist for “something for a retirement party” without pointing at any bouquets - you rely on what they already know about such occasions.
https://cmaintz.github.io/tech-atlas/en/terms/ai/zero-shot-prompting/ atlas ai prompting atlas-en-ai/zero-shot-prompting
Access control The rules and mechanisms that decide who may use which systems, data or rooms, and in what way.
Like the whole door system of an office building - the key-card readers, the list of who may enter which floor, and the lock that actually holds the door shut.
https://cmaintz.github.io/tech-atlas/en/terms/cs/access-control/ atlas cs security identity atlas-en-cs/access-control
User account A record in a system that lets a particular person or program log in, and holds the permissions it has been given.
Like a membership card at a gym - the card is not you, but it is how the gym knows you, what you have paid for and which classes you may join.
https://cmaintz.github.io/tech-atlas/en/terms/cs/account/ atlas cs identity atlas-en-cs/account
API A fixed set of requests one program offers so other programs can use its data or features without seeing its insides.
Like the menu and the waiter in a restaurant - you order from a fixed list, the kitchen does the work, and you never need to know how it is cooked.
https://cmaintz.github.io/tech-atlas/en/terms/cs/api/ atlas cs web atlas-en-cs/api
Audit logging A system's record of who did what, and when, for the actions that matter to security.
Like the visitor book and key-card record at a secure building's front desk - not what happened in general, but exactly who went where and when.
https://cmaintz.github.io/tech-atlas/en/terms/cs/audit/ atlas cs os atlas-en-cs/audit
Authentication Checking that someone who logs in really is who they claim to be, usually by asking for a credential such as a password.
Like a border guard comparing your face with your passport photo - the only question is “are you really you?”, not where you may go.
https://cmaintz.github.io/tech-atlas/en/terms/cs/authentication/ atlas cs security identity atlas-en-cs/authentication
Authorization Deciding what an already identified user is allowed to do, such as which files they may open or change.
Like the coloured band on your wrist at a festival - the gate already knows who you are, and the colour decides whether you may go backstage.
https://cmaintz.github.io/tech-atlas/en/terms/cs/authorization/ atlas cs security identity atlas-en-cs/authorization
Certificate authority (CA) A trusted body that checks who someone is and then signs digital certificates vouching that a public key belongs to them.
Like the passport office - it checks your papers before issuing a passport, and border guards accept the passport because they trust the office, not because they know you.
https://cmaintz.github.io/tech-atlas/en/terms/cs/certificate-authority/ atlas cs cryptography atlas-en-cs/certificate-authority
Client The program or device that starts a network exchange by sending a request, such as a web browser asking for a page.
Like a customer walking up to a shop counter - the customer asks, the shop answers, and it is always the customer who starts.
https://cmaintz.github.io/tech-atlas/en/terms/cs/client/ atlas cs networking atlas-en-cs/client
Conditional access Rules that decide at each login whether to let someone in, ask for more proof or block them, based on who, where and what device.
Like a doorman who knows the regulars - a familiar face at the usual time walks straight in, but the same name turning up at 3 a.m. from abroad has to show ID.
https://cmaintz.github.io/tech-atlas/en/terms/cs/conditional-access/ atlas cs security identity atlas-en-cs/conditional-access
Cookie A small piece of text a website asks the browser to keep and send back on every visit, so the site can recognise it.
Like the coat check ticket you get at a theatre - you hand it back each time, and the staff know which coat is yours without asking your name.
https://cmaintz.github.io/tech-atlas/en/terms/cs/cookie/ atlas cs web atlas-en-cs/cookie
Credential Something a user presents to prove who they are, such as a password, a key card or a fingerprint.
Like a house key - whoever holds it is let in, which is exactly why you do not lend it out or leave it under the doormat.
https://cmaintz.github.io/tech-atlas/en/terms/cs/credential/ atlas cs identity atlas-en-cs/credential
Cryptographic key The secret value that decides how data is scrambled and restored - whoever holds it can read the protected data.
Like the key to a padlock - everyone knows how padlocks work, but only the person with the right key can open this one.
https://cmaintz.github.io/tech-atlas/en/terms/cs/cryptographic-key/ atlas cs cryptography atlas-en-cs/cryptographic-key
Database An organised store of data that many programs and users can search, add to and change at the same time without mixing it up.
Like a well-run warehouse with a stock list - every item has a fixed place and a line in the list, so staff can find, add or move goods in seconds, and two clerks never undo each other's changes.
https://cmaintz.github.io/tech-atlas/en/terms/cs/database/ atlas cs web atlas-en-cs/database
Digital certificate A signed digital document that ties a public key to a name, such as a website address, so others can trust whose key it is.
Like a letter of introduction stamped by an authority both sides trust - the reader accepts the stranger because of the stamp, and only until the date written on it.
https://cmaintz.github.io/tech-atlas/en/terms/cs/digital-certificate/ atlas cs cryptography atlas-en-cs/digital-certificate
Digital signature A mark made with a private key that proves who sent a message and that nobody has changed it since.
Like a wax seal pressed with a ring only you own - anyone can compare the seal with your known pattern, and a broken seal shows the letter was opened.
https://cmaintz.github.io/tech-atlas/en/terms/cs/digital-signature/ atlas cs cryptography atlas-en-cs/digital-signature
DNS The lookup system that turns names people can read, like example.com, into IP addresses.
Like the contacts list on your phone - you tap a name, and the phone looks up the number for you.
https://cmaintz.github.io/tech-atlas/en/terms/cs/dns/ atlas cs networking atlas-en-cs/dns
Encryption Scrambling data with a secret key so only someone holding the matching key can read it.
Like writing a letter in a secret code only you and a friend know - anyone who steals the letter sees only gibberish.
https://cmaintz.github.io/tech-atlas/en/terms/cs/encryption/ atlas cs security networking atlas-en-cs/encryption
End-to-end encryption Scrambling a message on the sender's device so that only the receiver's device can read it, not even the service carrying it.
Like posting a locked box that only your friend has the key to - the postal service carries it all the way but can never open it.
https://cmaintz.github.io/tech-atlas/en/terms/cs/end-to-end-encryption/ atlas cs security cryptography atlas-en-cs/end-to-end-encryption
Identity federation An agreement between organisations to trust each other's logins, so a person proven at home is let in elsewhere.
Like countries that accept each other's passports - the border guard does not issue you a new one, but trusts the country that did.
https://cmaintz.github.io/tech-atlas/en/terms/cs/federation/ atlas cs identity atlas-en-cs/federation
File system The way an operating system organises stored data into files and folders and keeps track of who may use each one.
Like a filing cabinet with labelled drawers and folders, where each folder carries a note saying who owns it and who may take it out.
https://cmaintz.github.io/tech-atlas/en/terms/cs/file-system/ atlas cs os atlas-en-cs/file-system
Firewall A gatekeeper that checks network traffic against rules and lets through only what is allowed.
Like a guard at the gate of a building with a list of who may come in and which doors they may use; anyone not on the list is turned away.
https://cmaintz.github.io/tech-atlas/en/terms/cs/firewall/ atlas cs security networking atlas-en-cs/firewall
Hashing Turning any amount of data into a short, fixed-length value that changes completely if even one character changes.
Like a fingerprint - it identifies a person without containing the person, and nobody can rebuild someone from their fingerprint.
https://cmaintz.github.io/tech-atlas/en/terms/cs/hashing/ atlas cs cryptography atlas-en-cs/hashing
HTTP The request-and-answer rules a web browser and a server follow to fetch pages, pictures and data across the internet.
Like ordering at a counter by slip of paper - you write what you want, hand it over, and get back either the item or a note saying why not.
https://cmaintz.github.io/tech-atlas/en/terms/cs/http/ atlas cs web atlas-en-cs/http
HTTPS The way web browsers and websites exchange pages with TLS protecting every message, so no one on the way can read or change them.
Like ordering from a shop by sealed, tamper-proof envelope instead of shouting your order and card number across the street.
https://cmaintz.github.io/tech-atlas/en/terms/cs/https/ atlas cs networking atlas-en-cs/https
Digital identity The set of facts that lets a computer system tell one person, device or program apart from all others.
Like the details in a passport - name, birth date, photo - which together say who you are, before anyone has checked that it is really you.
https://cmaintz.github.io/tech-atlas/en/terms/cs/identity/ atlas cs identity atlas-en-cs/identity
Identity provider A trusted service that stores users' identities, checks their logins and vouches for them to other applications.
Like the passport office - it checks who you are once and issues a document that airlines and hotels accept without checking you from scratch.
https://cmaintz.github.io/tech-atlas/en/terms/cs/identity-provider/ atlas cs identity atlas-en-cs/identity-provider
Internet The worldwide network of networks that lets almost any connected device reach almost any other.
Like the world's post offices agreeing on one way to write addresses, so a letter posted in Denmark can reach a house in Tokyo.
https://cmaintz.github.io/tech-atlas/en/terms/cs/internet/ atlas cs networking atlas-en-cs/internet
IP address A number that identifies a device on a network so that data can be delivered to it.
Like a street address for a house - without it, the postman has no idea where to deliver the letter.
https://cmaintz.github.io/tech-atlas/en/terms/cs/ip-address/ atlas cs networking atlas-en-cs/ip-address
JSON A simple text format for writing down data as named values and lists, easy for both people and programs to read.
Like a neatly filled-in form where every box has a label, so anyone picking it up knows which answer belongs to which question.
https://cmaintz.github.io/tech-atlas/en/terms/cs/json/ atlas cs web atlas-en-cs/json
Kernel The core of the operating system, which has full control of the machine and decides what every program may do.
Like the staff at a bank vault - customers never walk into the vault themselves; they hand a slip over the counter, and staff decide whether to fetch what was asked for.
https://cmaintz.github.io/tech-atlas/en/terms/cs/kernel/ atlas cs os atlas-en-cs/kernel
Key management Looking after cryptographic keys over their whole life - making, storing, handing out, changing and finally destroying them.
Like a building manager's key cabinet - keys are cut, numbered, signed out, changed when a tenant moves and melted down when a lock is replaced.
https://cmaintz.github.io/tech-atlas/en/terms/cs/key-management/ atlas cs cryptography atlas-en-cs/key-management
Principle of least privilege Giving every user, program and service only the permissions its task needs, and nothing more.
Like giving a house-sitter the key to the front door but not to the safe - they can water the plants, and a lost key costs you less.
https://cmaintz.github.io/tech-atlas/en/terms/cs/least-privilege/ atlas cs identity atlas-en-cs/least-privilege
Log A time-stamped record of events that a system or program writes down as they happen.
Like the diary kept on a ship's bridge - the crew notes the time and what happened, entry after entry, so the voyage can be pieced together later.
https://cmaintz.github.io/tech-atlas/en/terms/cs/log/ atlas cs os atlas-en-cs/log
Network A set of connected devices that can send data to each other over cables or radio signals.
Like the roads between the houses in a town - once the roads are there, anyone can carry a letter from one door to another.
https://cmaintz.github.io/tech-atlas/en/terms/cs/network/ atlas cs networking atlas-en-cs/network
Network segmentation Splitting one network into separate zones, so a problem in one zone cannot easily spread to the others.
Like the watertight compartments in a ship - if one fills with water, the doors between them keep the whole ship from sinking.
https://cmaintz.github.io/tech-atlas/en/terms/cs/network-segmentation/ atlas cs security networking atlas-en-cs/network-segmentation
OAuth A way to let one app act on your behalf in another service, with a limited pass instead of your password.
Like a valet key for a car - it lets the attendant drive and park, but not open the boot or the glove box, and you never hand over your own key.
https://cmaintz.github.io/tech-atlas/en/terms/cs/oauth/ atlas cs identity atlas-en-cs/oauth
OpenID Connect (OIDC) A login standard built on top of OAuth that tells an app who the user is, not just what it may do.
Like a valet key handed over together with a signed name badge - the key says what the holder may do with the car, the badge says who the holder is.
https://cmaintz.github.io/tech-atlas/en/terms/cs/openid-connect/ atlas cs identity atlas-en-cs/openid-connect
Operating system The base software that runs a computer, shares it between programs and keeps them from interfering with each other.
Like the management of an apartment building - tenants share the water, heat and stairs, and the management makes sure no one takes everything or walks into someone else's flat.
https://cmaintz.github.io/tech-atlas/en/terms/cs/operating-system/ atlas cs os atlas-en-cs/operating-system
Packet A small, labelled chunk of data that travels across a network on its own and is put back together at the end.
Like sending a book by post one page at a time, each page in its own addressed envelope, and reassembling the book when all envelopes arrive.
https://cmaintz.github.io/tech-atlas/en/terms/cs/packet/ atlas cs networking atlas-en-cs/packet
Passkey A login without a password, where your device proves who you are with a secret key that never leaves it.
Like a key that never leaves your key ring and turns only in your own front door - there is no code to say out loud, so a fake door gets nothing from you.
https://cmaintz.github.io/tech-atlas/en/terms/cs/passkey/ atlas cs identity atlas-en-cs/passkey
Password A secret string of characters, known only to the user, typed in to prove they are who they claim to be.
Like a secret knock agreed with a friend - it works only while nobody else knows it, and it is useless once someone has overheard it.
https://cmaintz.github.io/tech-atlas/en/terms/cs/password/ atlas cs identity atlas-en-cs/password
Patch A small piece of software from a vendor that fixes a flaw - often a vulnerability - in a program already installed.
Like a car maker calling cars back so the garage can swap one faulty part - the car stays the same, but the known defect is gone.
https://cmaintz.github.io/tech-atlas/en/terms/cs/patch/ atlas cs os atlas-en-cs/patch
Permission A specific right given to an account, such as to read, change or delete a file, or to run a program.
Like the keys on a caretaker's ring - each key opens particular doors, and the key to the boiler room does not open the office.
https://cmaintz.github.io/tech-atlas/en/terms/cs/permission/ atlas cs os atlas-en-cs/permission
Port A number that picks out which program on a device should receive incoming network data.
If the street address gets a letter to the right building, this number is the flat number - it says which door inside the building the letter goes to.
https://cmaintz.github.io/tech-atlas/en/terms/cs/port/ atlas cs networking atlas-en-cs/port
Privileged access management (PAM) Tools and rules that lock away admin rights, hand them out only when needed and record what is done with them.
Like the key cabinet in a bank - the vault key is signed out for one job, the time is written down, a camera watches, and the key goes back afterwards.
https://cmaintz.github.io/tech-atlas/en/terms/cs/privileged-access-management/ atlas cs security identity atlas-en-cs/privileged-access-management
Privileged account An account with power beyond normal use, such as installing software, changing settings or managing other users.
Like the master key in a hotel that opens every room - handy for the manager, but a disaster if it is lost or copied.
https://cmaintz.github.io/tech-atlas/en/terms/cs/privileged-account/ atlas cs identity atlas-en-cs/privileged-account
Process A program while it is running, with its own space in memory and the rights of the account that started it.
A recipe is the program; actually cooking it in a kitchen, with your own pots and ingredients, is the process. Two cooks can follow the same recipe at the same time.
https://cmaintz.github.io/tech-atlas/en/terms/cs/process/ atlas cs os atlas-en-cs/process
Protocol An agreed set of rules for how devices on a network format, send and answer messages.
Like the rules everyone follows on a phone call - you say hello, wait for an answer, take turns and say goodbye before hanging up.
https://cmaintz.github.io/tech-atlas/en/terms/cs/protocol/ atlas cs networking atlas-en-cs/protocol
Public-key cryptography Encryption that uses a pair of keys - one shared openly, one kept private - so strangers can protect data for you without a shared secret.
Like a mailbox with a slot - anyone can drop a letter in, but only the owner has the key to take letters out.
https://cmaintz.github.io/tech-atlas/en/terms/cs/public-key-cryptography/ atlas cs cryptography atlas-en-cs/public-key-cryptography
Public key infrastructure (PKI) The system of trusted issuers, rules and records that hands out digital certificates and says which ones to believe.
Like the passport system - a few governments everyone trusts issue passports, border guards know what a real one looks like, and lost ones are reported as no longer valid.
https://cmaintz.github.io/tech-atlas/en/terms/cs/public-key-infrastructure/ atlas cs cryptography atlas-en-cs/public-key-infrastructure
REST API A common style of web API where each thing has its own URL and programs use plain HTTP methods to read, add, change or delete it.
Like a library where every book has a fixed shelf number, and there are only a handful of desk requests - borrow, return, add, remove - that work the same for every book.
https://cmaintz.github.io/tech-atlas/en/terms/cs/rest-api/ atlas cs web atlas-en-cs/rest-api
Role-based access control (RBAC) Giving permissions to job roles rather than to individual people, and then giving people the roles that fit their job.
Like staff uniforms in a hotel - the uniform, not the person, decides which areas you may enter, and a new waiter simply gets the waiter's uniform.
https://cmaintz.github.io/tech-atlas/en/terms/cs/role-based-access-control/ atlas cs identity atlas-en-cs/role-based-access-control
Router A device that joins networks together and passes each packet on toward its destination.
Like a sorting office at the post - it does not open letters, it just reads the address and sends each one down the right road.
https://cmaintz.github.io/tech-atlas/en/terms/cs/router/ atlas cs networking atlas-en-cs/router
Same-origin policy A browser rule that stops a page from one site reading data that belongs to another site open in the same browser.
Like hotel rooms on one key card system - your card works for your own room, and you can knock on any door, but you cannot walk in and read what lies on the next guest's desk.
https://cmaintz.github.io/tech-atlas/en/terms/cs/same-origin-policy/ atlas cs security web atlas-en-cs/same-origin-policy
SAML An older, widely used standard for passing a signed “this user has logged in” message from an identity provider to an app.
Like a sealed letter of introduction from your employer - the hotel does not know you, but it knows the seal and lets you in.
https://cmaintz.github.io/tech-atlas/en/terms/cs/saml/ atlas cs identity atlas-en-cs/saml
Secure boot A start-up check that lets a computer run only boot software and a kernel carrying a trusted digital signature.
Like a guard at the factory gate who checks every driver's badge before the working day starts, so nobody can slip in while the lights are still off.
https://cmaintz.github.io/tech-atlas/en/terms/cs/secure-boot/ atlas cs security os atlas-en-cs/secure-boot
Server A computer or program that waits for requests over a network and answers them, such as sending a web page or storing email.
Like the counter at a library - it stays open, waits for people to ask for a book, and hands over what they asked for.
https://cmaintz.github.io/tech-atlas/en/terms/cs/server/ atlas cs networking atlas-en-cs/server
Service A program that runs in the background without a user, often starting with the computer and waiting to handle requests.
Like a night porter - nobody sees them working, but they are always on duty and ready when someone rings the bell.
https://cmaintz.github.io/tech-atlas/en/terms/cs/service/ atlas cs os atlas-en-cs/service
Service account An account used by a program rather than a person, so that software can log in to other systems on its own.
Like a key card issued to the cleaning robot rather than to a worker - it opens only the doors the robot needs, at any hour, with nobody holding it.
https://cmaintz.github.io/tech-atlas/en/terms/cs/service-account/ atlas cs identity atlas-en-cs/service-account
Session The period in which a system remembers that a user has logged in, so they need not prove who they are at every step.
Like the hand stamp at a club - you show ID once at the door, then the stamp lets you back in all evening, until it washes off.
https://cmaintz.github.io/tech-atlas/en/terms/cs/session/ atlas cs identity atlas-en-cs/session
Single sign-on (SSO) Logging in once to reach many separate applications, with a trusted identity provider vouching for the user to each.
Like a hotel key card from reception - you prove who you are once at the desk, and the gym, the pool and your room all trust the card.
https://cmaintz.github.io/tech-atlas/en/terms/cs/single-sign-on/ atlas cs identity atlas-en-cs/single-sign-on
Symmetric encryption Encryption where the same secret key both locks and unlocks the data, so sender and receiver must share it in advance.
Like a padlocked box where you and a friend each hold a copy of the same key - easy to use, but you had to hand the copy over in person first.
https://cmaintz.github.io/tech-atlas/en/terms/cs/symmetric-encryption/ atlas cs cryptography atlas-en-cs/symmetric-encryption
TCP/IP The family of protocols that the internet and most other networks use to address, send and deliver data.
IP is the post office that moves envelopes; TCP is the careful clerk who numbers them, checks every one arrived, and asks again for any that went missing.
https://cmaintz.github.io/tech-atlas/en/terms/cs/tcp-ip/ atlas cs networking atlas-en-cs/tcp-ip
TLS The protocol that wraps data sent over TCP/IP in an encrypted channel after checking the other side's certificate.
Like sending your letters in a locked, sealed case, after first checking the person receiving it is really who they claim to be.
https://cmaintz.github.io/tech-atlas/en/terms/cs/tls/ atlas cs networking atlas-en-cs/tls
URL A written address that says where something lives on the internet and how to reach it, such as a web page or a file.
Like a postal address with a delivery note - the town and street get you to the building, and the rest says which flat and which letter box.
https://cmaintz.github.io/tech-atlas/en/terms/cs/url/ atlas cs web atlas-en-cs/url
VPN An encrypted tunnel across a public network that makes a distant device act as if it were inside a private one.
Like a private, sealed tunnel from your home straight into the office building, so the walk through the busy public street no longer matters.
https://cmaintz.github.io/tech-atlas/en/terms/cs/vpn/ atlas cs networking atlas-en-cs/vpn
Web application A program you use through a web browser, with its logic and data kept on a server instead of installed on your own machine.
Like a bank counter seen through a window - you fill in slips and get answers at the glass, while the safe, the ledgers and the staff doing the work stay out of sight behind it.
https://cmaintz.github.io/tech-atlas/en/terms/cs/web-application/ atlas cs web atlas-en-cs/web-application
Web browser The program people use to visit websites - it fetches pages from servers and turns them into something you can read and click.
Like a television set for the web - the shows are made and sent elsewhere, and the set just tunes in and plays them for you.
https://cmaintz.github.io/tech-atlas/en/terms/cs/web-browser/ atlas cs web atlas-en-cs/web-browser
Alerting Rules that tell the right person, at once, when a system needs human attention, and stay quiet when it does not.
Like a smoke alarm; it must go off for a real fire, but if it screams every time someone makes toast, people start taking the battery out.
https://cmaintz.github.io/tech-atlas/en/terms/platform/alerting/ atlas platform observability atlas-en-platform/alerting
CI/CD Merging, testing and releasing small software changes automatically and often, instead of in rare, large batches.
Like a bakery that checks and ships each tray as soon as it leaves the oven, rather than baking for a month and discovering on delivery day that the recipe was wrong.
https://cmaintz.github.io/tech-atlas/en/terms/platform/ci-cd/ atlas platform delivery atlas-en-platform/ci-cd
Cloud computing Renting computing power, storage and software over the internet from a provider, paying for what you use instead of owning it.
Like getting electricity from the grid instead of running your own generator - you plug in, use what you need and pay the bill.
https://cmaintz.github.io/tech-atlas/en/terms/platform/cloud-computing/ atlas platform cloud atlas-en-platform/cloud-computing
Cloud IAM The cloud provider's built-in system of policies that decides which users, roles and service accounts may do what to each resource.
Like the key card system in an office building - one central list says whose card opens which doors, and every door checks that list each time.
https://cmaintz.github.io/tech-atlas/en/terms/platform/cloud-iam/ atlas platform security cloud atlas-en-platform/cloud-iam
Cloud misconfiguration A wrong or careless setting in a cloud service - like storage left open to everyone - that exposes data or systems.
Like a sturdy safe bought for the office but left with its door standing open - the safe works fine; the way it was set up does not.
https://cmaintz.github.io/tech-atlas/en/terms/platform/cloud-misconfiguration/ atlas platform security cloud atlas-en-platform/cloud-misconfiguration
Code signing Adding a digital signature to software so users and systems can check who made it and that nobody changed it afterwards.
Like the seal on a medicine bottle printed with the maker's name - if the seal is broken or the name is wrong, you do not swallow what is inside.
https://cmaintz.github.io/tech-atlas/en/terms/platform/code-signing/ atlas platform security delivery atlas-en-platform/code-signing
Container A sealed-off box for one program and everything it needs, sharing the host computer's kernel instead of carrying its own.
Like shipping containers on one cargo ship - each holds its own goods in a standard box, but they all ride on the same hull and engine.
https://cmaintz.github.io/tech-atlas/en/terms/platform/container/ atlas platform containers atlas-en-platform/container
Container escape An attack where code running inside a container breaks out of it and gains control of the host machine beneath it.
Like a guest in one hotel room who finds a loose wall panel and suddenly walks into the hotel's back office.
https://cmaintz.github.io/tech-atlas/en/terms/platform/container-escape/ atlas platform security containers atlas-en-platform/container-escape
Container image The frozen, read-only package of a program and its files from which identical containers are started.
Like a cake recipe with the ingredients already measured out - every cake baked from it comes out the same, and the recipe itself is never eaten.
https://cmaintz.github.io/tech-atlas/en/terms/platform/container-image/ atlas platform containers atlas-en-platform/container-image
Container orchestration Letting software run many containers across a group of machines automatically, so nobody has to start and place them by hand.
Like the conductor of an orchestra - the musicians play their own parts, but someone decides who plays when, and brings in a stand-in if one falls ill.
https://cmaintz.github.io/tech-atlas/en/terms/platform/container-orchestration/ atlas platform containers atlas-en-platform/container-orchestration
Container registry A shared online store where container images are uploaded, given names and versions, and fetched by the machines that run them.
Like a library for software boxes - builders hand in new editions, and every machine borrows the exact edition it asks for by name.
https://cmaintz.github.io/tech-atlas/en/terms/platform/container-registry/ atlas platform containers atlas-en-platform/container-registry
Container runtime The software on each host that actually starts, stops and walls off containers - containerd is a well-known example.
Like the engine room of a ship - the captain gives the orders, but this is where the machinery actually turns them into movement.
https://cmaintz.github.io/tech-atlas/en/terms/platform/container-runtime/ atlas platform containers atlas-en-platform/container-runtime
DevSecOps Building security checks into the everyday work of the teams that write and run software, rather than adding them at the end.
Like building a house with the fire inspector on site from day one, instead of calling them in when the keys are about to be handed over.
https://cmaintz.github.io/tech-atlas/en/terms/platform/devsecops/ atlas platform security delivery atlas-en-platform/devsecops
Distributed tracing Following one user request as it passes through many services, timing each step, to see where it slowed down or failed.
Like the tracking page for a parcel, showing each depot it passed and how long it sat there, so you can see it was stuck three days in one place.
https://cmaintz.github.io/tech-atlas/en/terms/platform/distributed-tracing/ atlas platform observability atlas-en-platform/distributed-tracing
Docker The widely used tool that made containers easy to use - it builds container images, shares them and runs them with a few commands.
Like a standard shipping company for software - it packs the goods into the same kind of box every time and delivers them anywhere that accepts that box.
https://cmaintz.github.io/tech-atlas/en/terms/platform/docker/ atlas platform containers atlas-en-platform/docker
GitOps Running systems so that files under version control hold the only true description, and software keeps the live setup matching them.
Like a shop where the price list on the wall is the rule; if someone changes a price tag on the shelf, staff put it back to match the wall.
https://cmaintz.github.io/tech-atlas/en/terms/platform/gitops/ atlas platform delivery atlas-en-platform/gitops
Health check A small automatic test, repeated every few seconds, that asks a running service whether it is alive and able to answer.
Like a lifeguard who calls out to each swimmer now and then; anyone who does not answer gets pulled out of the water.
https://cmaintz.github.io/tech-atlas/en/terms/platform/health-check/ atlas platform observability atlas-en-platform/health-check
Hypervisor The layer of software that splits one physical computer into several virtual machines and keeps them apart.
Like the caretaker of an apartment block who divides up the space, water and heat between the flats and makes sure no tenant can walk into a neighbour's home.
https://cmaintz.github.io/tech-atlas/en/terms/platform/hypervisor/ atlas platform cloud atlas-en-platform/hypervisor
Infrastructure as a service (IaaS) The cloud model where you rent bare building blocks - machines, storage and network - and run everything on top yourself.
Like renting an empty warehouse - the landlord keeps the walls and roof sound, but the shelves, locks and stock inside are up to you.
https://cmaintz.github.io/tech-atlas/en/terms/platform/iaas/ atlas platform cloud atlas-en-platform/iaas
Infrastructure as code (IaC) Describing servers, networks and cloud settings in text files that a tool reads to build them, instead of setting them up by hand.
Like a detailed recipe instead of a chef's memory; anyone can cook the same dish again, and you can see exactly which ingredient changed since last time.
https://cmaintz.github.io/tech-atlas/en/terms/platform/infrastructure-as-code/ atlas platform delivery atlas-en-platform/infrastructure-as-code
Kubernetes The most widely used open-source system for container orchestration, first built at Google and released in 2014.
Like a thermostat for software - you set how many copies should be running, and it keeps adding or removing them until reality matches.
https://cmaintz.github.io/tech-atlas/en/terms/platform/kubernetes/ atlas platform containers atlas-en-platform/kubernetes
Metrics Numbers a system records at regular times, such as requests per second or memory used, so trends can be charted and compared.
Like the readings on your electricity meter taken every hour; one number on its own says little, but the curve over a week shows when something unusual happened.
https://cmaintz.github.io/tech-atlas/en/terms/platform/metrics/ atlas platform observability atlas-en-platform/metrics
Microservices A way of building an application as many small, separate services that each do one job and talk to each other over an API.
Like a food court instead of one big kitchen - each stall cooks one thing, can close for repairs on its own, and customers order from several at once.
https://cmaintz.github.io/tech-atlas/en/terms/platform/microservices/ atlas platform cs containers atlas-en-platform/microservices
Monitoring Watching a set of chosen measurements on systems over time and warning people when one moves outside its normal range.
Like the warning lights on a car's dashboard; they tell you quickly that the oil is low, but not why the engine is making a strange noise.
https://cmaintz.github.io/tech-atlas/en/terms/platform/monitoring/ atlas platform observability atlas-en-platform/monitoring
Observability How well you can work out what is going on inside a running system just from the signals it sends out.
Like a doctor who can find out why you are ill from blood tests, scans and your own story, not just from whether you have a fever.
https://cmaintz.github.io/tech-atlas/en/terms/platform/observability/ atlas platform observability atlas-en-platform/observability
Platform as a service (PaaS) The cloud model where the provider runs the machines and operating system, and you only bring your own program and its data.
Like renting a fully equipped restaurant kitchen - ovens, gas and cleaning are handled, and you just bring your recipes and ingredients.
https://cmaintz.github.io/tech-atlas/en/terms/platform/paas/ atlas platform cloud atlas-en-platform/paas
Pipeline A fixed, automatic chain of steps that takes a code change from saved file to running software, stopping if any step fails.
Like a car factory's assembly line, where each station does one job and a car that fails the brake test never reaches the showroom.
https://cmaintz.github.io/tech-atlas/en/terms/platform/pipeline/ atlas platform delivery atlas-en-platform/pipeline
Pod The smallest unit Kubernetes runs - one or a few tightly linked containers that share a network address and storage.
Like two people sharing one flat - same address, same fridge, and when they move, they move together.
https://cmaintz.github.io/tech-atlas/en/terms/platform/pod/ atlas platform containers atlas-en-platform/pod
Runbook Written step-by-step instructions for handling one known situation, such as a certain alarm, so anyone on call can act fast.
Like the checklist pilots pull out when a warning light comes on; nobody has to invent the answer under stress.
https://cmaintz.github.io/tech-atlas/en/terms/platform/runbook/ atlas platform observability atlas-en-platform/runbook
Software as a service (SaaS) The cloud model where you simply use a finished program over the internet, and the provider runs everything behind it.
Like taking a taxi instead of owning a car - you say where to go, and someone else handles the engine, the fuel and the repairs.
https://cmaintz.github.io/tech-atlas/en/terms/platform/saas/ atlas platform cloud atlas-en-platform/saas
Software bill of materials (SBOM) A list of every component and outside library a piece of software contains, so its owners know exactly what is inside it.
Like the parts list that comes with a car; when a maker recalls a faulty brake part, every owner can quickly check whether their car has it.
https://cmaintz.github.io/tech-atlas/en/terms/platform/sbom/ atlas platform security delivery atlas-en-platform/sbom
Secrets management Keeping passwords, keys and tokens that programs use in one guarded store, instead of scattered in code and files.
Like a hotel key desk that hands out room keys only to the right guests, notes who took which key and can cancel a lost one at once - instead of keys hidden under doormats.
https://cmaintz.github.io/tech-atlas/en/terms/platform/secrets-management/ atlas platform security cloud atlas-en-platform/secrets-management
Service level agreement (SLA) A written promise in a contract about how well a service will work, with a price to pay, such as money back, if it is broken.
Like a pizza place that promises delivery in thirty minutes or the pizza is free; the promise only means something because breaking it costs them.
https://cmaintz.github.io/tech-atlas/en/terms/platform/service-level-agreement/ atlas platform observability atlas-en-platform/service-level-agreement
Service level objective (SLO) An internal target for how well a service should work, such as 99.9% of requests answered within a second over 30 days.
Like a bus company aiming for 98% of buses on time; the timetable it prints for passengers promises less, so it has room to spare before it owes anyone money.
https://cmaintz.github.io/tech-atlas/en/terms/platform/service-level-objective/ atlas platform observability atlas-en-platform/service-level-objective
Shared responsibility model The split of security duties between a cloud provider and its customer, which shifts with the kind of service bought.
Like renting a flat - the landlord must keep the front door lock and the wiring safe, but locking your own door and not handing out spare keys is up to you.
https://cmaintz.github.io/tech-atlas/en/terms/platform/shared-responsibility-model/ atlas platform security cloud atlas-en-platform/shared-responsibility-model
Software composition analysis (SCA) Automatic checking of the outside libraries a program is built from, looking for known flaws and licence problems.
Like a food inspector who reads the label of every ingredient a bakery buys in and checks each against the list of recalled products.
https://cmaintz.github.io/tech-atlas/en/terms/platform/software-composition-analysis/ atlas platform security delivery atlas-en-platform/software-composition-analysis
Software supply chain Everything and everyone that goes into making software you run, from outside code parts to the tools that build and ship it.
Like a food chain from farm to table; if one supplier's flour is poisoned, every bakery that bought it, and every customer, is affected, however clean their own kitchen is.
https://cmaintz.github.io/tech-atlas/en/terms/platform/software-supply-chain/ atlas platform security delivery atlas-en-platform/software-supply-chain
Telemetry The data a running system sends out about itself, mainly logs, metrics and traces, so people can see how it is doing.
Like the readings a hospital monitor sends to the nurses' desk, such as heart rate and oxygen, so nobody has to stand by the bed to know how the patient is.
https://cmaintz.github.io/tech-atlas/en/terms/platform/telemetry/ atlas platform observability atlas-en-platform/telemetry
Version control A system that keeps every saved version of a set of files, with who changed what and when, so work can be compared or rolled back.
Like the full edit history of a shared document, where you can see every earlier draft, who wrote each line, and go back to last Tuesday's copy with one click.
https://cmaintz.github.io/tech-atlas/en/terms/platform/version-control/ atlas platform delivery atlas-en-platform/version-control
Virtual machine A whole computer made in software, with its own operating system, running side by side with others on one physical machine.
Like flats in one building - each has its own front door, kitchen and bathroom, even though they share the same foundations.
https://cmaintz.github.io/tech-atlas/en/terms/platform/virtual-machine/ atlas platform cloud atlas-en-platform/virtual-machine
Access management The rules and routines that decide who may use which data and systems, and that keep those rights correct over time.
Like the office manager who decides who gets a key to which rooms, and collects the keys back when someone changes job or leaves.
https://cmaintz.github.io/tech-atlas/en/terms/security/access-management/ atlas security controls atlas-en-security/access-management
Alert triage Sorting incoming alarms quickly into real threats, harmless noise and cases that need a closer look, so the worst get handled first.
Like the nurse at a hospital's emergency desk who looks at everyone coming in and decides who sees a doctor now, who can wait, and who can go home.
https://cmaintz.github.io/tech-atlas/en/terms/security/alert-triage/ atlas security security-operations atlas-en-security/alert-triage
ISO 27001 Annex A The list of 93 reference controls at the back of ISO 27001 that every organisation using the standard must hold its own controls up against.
Like planning a set dinner from a restaurant's full menu - you read every dish, pick the ones that suit your guests, and can say why the rest were left off.
https://cmaintz.github.io/tech-atlas/en/terms/security/annex-a/ atlas security compliance atlas-en-security/annex-a
Anomaly detection Learning what normal activity looks like and raising an alarm when something departs from it, even if no rule describes the attack.
Like a bank teller who knows a regular customer so well that she notices at once when he asks to move all his savings abroad on a Sunday.
https://cmaintz.github.io/tech-atlas/en/terms/security/anomaly-detection/ atlas security ai security-operations atlas-en-security/anomaly-detection
API security Protecting the APIs that programs use to talk to each other, so each caller can reach and change only what it is allowed to.
Like a bank cashier who checks not only who you are but also that the account you ask about is really yours - every single time.
https://cmaintz.github.io/tech-atlas/en/terms/security/api-security/ atlas security application-security atlas-en-security/api-security
Asset Anything of value to the organisation that needs protecting - data, systems, devices, people or know-how.
Everything you would worry about if your home caught fire - the laptop, the family photos, the house keys, and the one person who knows where everything is kept.
https://cmaintz.github.io/tech-atlas/en/terms/security/asset/ atlas security fundamentals atlas-en-security/asset
Asset inventory One complete, up-to-date list of the organisation's computers, devices, systems and software.
Like the list a household makes for home insurance - you cannot protect or claim for what you do not know you have.
https://cmaintz.github.io/tech-atlas/en/terms/security/asset-inventory/ atlas security controls atlas-en-security/asset-inventory
Attack surface The sum of all the places where an outsider could try to get into a system, send data into it or pull data out.
Like counting every door, window, hatch and mail slot in a house - each one is a place a burglar could try, whether or not it is locked.
https://cmaintz.github.io/tech-atlas/en/terms/security/attack-surface/ atlas security application-security atlas-en-security/attack-surface
Audit An independent check of whether an organisation actually follows its own policies and the requirements it has signed up to.
Like the regular car inspection - the owner may say the brakes are fine, but the inspector puts the car on the test bench and checks for real.
https://cmaintz.github.io/tech-atlas/en/terms/security/audit/ atlas security compliance atlas-en-security/audit
Authentication factor One kind of proof used to log in - something you know, something you have, or something you are.
Like the ways a nursery checks who may collect a child - a secret word agreed in advance, a note from the parent, or a teacher who knows the parent's face; three different kinds of proof.
https://cmaintz.github.io/tech-atlas/en/terms/security/authentication-factor/ atlas security cs controls atlas-en-security/authentication-factor
Availability Making sure information and systems can be used by the right people when they are needed.
Like a shop's opening hours - the goods are no use to anyone if the door is locked when customers arrive.
https://cmaintz.github.io/tech-atlas/en/terms/security/availability/ atlas security fundamentals atlas-en-security/availability
Awareness maturity A measure of how far an organisation has come in making security part of how its people think and act.
Like the swimming badges children earn in stages - a badge does not make them swim better, but it shows honestly where they are and what the next step is.
https://cmaintz.github.io/tech-atlas/en/terms/security/awareness-maturity/ atlas security awareness atlas-en-security/awareness-maturity
Awareness officer The person responsible for teaching staff to spot and avoid attacks, and for measuring whether their habits actually change.
Like the dental nurse who teaches children to brush - the aim is fewer holes later, and the next check-up shows whether the lesson stuck.
https://cmaintz.github.io/tech-atlas/en/terms/security/awareness-officer/ atlas security awareness atlas-en-security/awareness-officer
Awareness programme A planned, ongoing effort to change how staff behave around security - with target groups, messages, methods and measurable goals.
Like a fitness plan rather than a single gym visit - small, regular sessions matched to each person, with progress checked along the way.
https://cmaintz.github.io/tech-atlas/en/terms/security/awareness-programme/ atlas security awareness atlas-en-security/awareness-programme
Backup A separate copy of data kept so it can be restored after a breakdown, a mistake or an attack.
Like keeping paper copies of your passport and deeds at a relative's house - if your home burns down, the papers are not lost.
https://cmaintz.github.io/tech-atlas/en/terms/security/backup/ atlas security cs controls atlas-en-security/backup
Business continuity plan (BCP) A plan for keeping the most important work going during and after a crisis, even while the systems are down.
Like a shop that keeps selling with a paper notebook and cash when the card terminal dies.
https://cmaintz.github.io/tech-atlas/en/terms/security/business-continuity-plan/ atlas security incident-response atlas-en-security/business-continuity-plan
Business email compromise (CEO fraud) A scam where criminals pose as a boss or supplier by email to trick staff into paying money or sending data.
Like a forged note that looks exactly as if it came from the boss, telling you to hand the cash box to the person at the door.
https://cmaintz.github.io/tech-atlas/en/terms/security/business-email-compromise/ atlas security awareness atlas-en-security/business-email-compromise
Business impact analysis (BIA) A study of what an outage or incident would do to the business, and how long each activity can be down.
Like a restaurant asking which hurts more if it breaks, the oven or the coffee machine, and how many hours it could cope without each.
https://cmaintz.github.io/tech-atlas/en/terms/security/business-impact-analysis/ atlas security risk-management atlas-en-security/business-impact-analysis
CER Directive The EU law that makes the operators of vital services like power and water able to withstand floods, sabotage and other physical threats.
Protecting a dam is not only about who knows the control-room code - it is also the fence, the spare generator and the plan for the day the river rises.
https://cmaintz.github.io/tech-atlas/en/terms/security/cer-directive/ atlas security compliance atlas-en-security/cer-directive
Certification Formal proof from an approved outside body that an organisation's security meets a published standard such as ISO 27001.
Like a driving test - you may already drive carefully, but only the examiner's pass gives you a licence that strangers will trust.
https://cmaintz.github.io/tech-atlas/en/terms/security/certification/ atlas security compliance atlas-en-security/certification
Centre for Cyber Security (CFCS) Denmark's national cyber security body from 2012, which in January 2025 became part of the Danish Resilience Agency (SAMSIK).
Like a national weather service for storms on the internet - it watched the sky, sent out warnings and told people how to prepare, and was later folded into a larger agency.
https://cmaintz.github.io/tech-atlas/en/terms/security/cfcs/ atlas security compliance atlas-en-security/cfcs
Change management A controlled process to plan, approve, record and check every change made to IT systems.
Like a building project where no wall comes down until the plans are approved, the neighbours are told, and there is a way to put it back up.
https://cmaintz.github.io/tech-atlas/en/terms/security/change-management/ atlas security controls atlas-en-security/change-management
CIA triad The three pillars of information security - confidentiality, integrity and availability.
Like a three-legged stool - if any one leg is missing, the whole thing falls over.
https://cmaintz.github.io/tech-atlas/en/terms/security/cia-triad/ atlas security fundamentals atlas-en-security/cia-triad
CIS Controls A ranked, public list of security measures from the Center for Internet Security that tells an organisation what to do first.
Like a checklist from a fire safety expert that says "fit smoke alarms before you buy a sprinkler system" - it tells you which protections give the most for the least.
https://cmaintz.github.io/tech-atlas/en/terms/security/cis-controls/ atlas security controls atlas-en-security/cis-controls
Communication plan A plan for who tells what to whom during a crisis - staff, customers, authorities and the press.
Like agreeing in advance who in the family calls grandma with bad news, so she does not hear it first from the neighbours.
https://cmaintz.github.io/tech-atlas/en/terms/security/communication-plan/ atlas security incident-response atlas-en-security/communication-plan
Compliance Living up to the laws, rules and standards that apply - for example NIS2, GDPR or ISO 27001.
Like a car passing its road-worthiness check - it proves the car meets the rules, but not that it is driven safely.
https://cmaintz.github.io/tech-atlas/en/terms/security/compliance/ atlas security fundamentals atlas-en-security/compliance
Compliance and risk coordinator A role, often a first job in the field, that tracks which rules apply, where the organisation falls short, and how its risks are handled.
Like a bookkeeper for rules - keeping the list of what is owed, what is paid and what is overdue, so there are no surprises when the inspector comes.
https://cmaintz.github.io/tech-atlas/en/terms/security/compliance-and-risk-coordinator/ atlas security compliance atlas-en-security/compliance-and-risk-coordinator
Compliance roadmap A time plan that turns a list of gaps into ordered steps, owners and dates for meeting a set of requirements.
Like planning a house renovation - first the roof that leaks, then the wiring, and the new kitchen last - each job with a builder and a week.
https://cmaintz.github.io/tech-atlas/en/terms/security/compliance-roadmap/ atlas security compliance atlas-en-security/compliance-roadmap
Confidentiality Making sure only the right people can see a piece of information.
Like a sealed letter - the address is on the outside, but only the person it is meant for should read what is inside.
https://cmaintz.github.io/tech-atlas/en/terms/security/confidentiality/ atlas security fundamentals atlas-en-security/confidentiality
Contingency plan A written, approved plan for how the organisation reacts when something goes wrong - who does what, and in which order.
Like the fire instructions on the back of a hotel room door, but written for the whole organisation.
https://cmaintz.github.io/tech-atlas/en/terms/security/contingency-plan/ atlas security incident-response atlas-en-security/contingency-plan
Security control A measure that lowers risk - technical, like a lock on a system, or organisational, like a rule or training.
Like a smoke alarm, a fire door and a fire drill - three different kinds of measure against the same danger.
https://cmaintz.github.io/tech-atlas/en/terms/security/control/ atlas security fundamentals atlas-en-security/control
Credential stuffing Trying stolen user names and passwords from one leak on many other sites, hoping people used the same password there.
A thief finds your house key on the street and then tries it on your car, your office and your summer house - just in case.
https://cmaintz.github.io/tech-atlas/en/terms/security/credential-stuffing/ atlas security fundamentals atlas-en-security/credential-stuffing
Crisis management How top management leads the whole organisation through a serious event - decisions, priorities, staff, customers and press.
Like parents after a house fire - the fire brigade fights the flames, but the parents decide where the family sleeps tonight, who calls the insurer and what to tell the children.
https://cmaintz.github.io/tech-atlas/en/terms/security/crisis-management/ atlas security incident-response atlas-en-security/crisis-management
Critical assets The systems, processes or data the business cannot run without, and so must protect first.
Like the few things you would grab first if your house were on fire - passports, medicine, family photos - rather than the sofa.
https://cmaintz.github.io/tech-atlas/en/terms/security/critical-assets/ atlas security risk-management atlas-en-security/critical-assets
Cross-site request forgery (CSRF) An attack where a harmful page makes a user's browser send a request to a site they are logged in to, which acts as if they asked.
Like someone slipping a signed order form into your post - the shop sees your signature and fills the order, never asking whether you meant to send it.
https://cmaintz.github.io/tech-atlas/en/terms/security/cross-site-request-forgery/ atlas security application-security atlas-en-security/cross-site-request-forgery
Cross-site scripting (XSS) An attack that smuggles a harmful script into a web page, so it runs in the browser of everyone who visits the page.
Like a notice board where someone pins up a note that, when read aloud, makes the reader hand over their house keys - the board itself never checks what is pinned to it.
https://cmaintz.github.io/tech-atlas/en/terms/security/cross-site-scripting/ atlas security application-security atlas-en-security/cross-site-scripting
CSRF token A secret, hard-to-guess value a site puts in its own forms and checks on every change, so requests started by other sites fail.
Like a shop that stamps a one-off number on every order form it hands out, and only accepts forms that come back with the number it gave you.
https://cmaintz.github.io/tech-atlas/en/terms/security/csrf-token/ atlas security application-security atlas-en-security/csrf-token
CVE and CVSS A public ID number for each known weakness in software (CVE), plus a 0-10 score for how serious it is (CVSS).
Like a hurricane that gets a name and, separately, a category from 1 to 5 - the name says which storm is meant, the category how bad it is.
https://cmaintz.github.io/tech-atlas/en/terms/security/cve/ atlas security risk-management atlas-en-security/cve
Cyber and information security Protecting an organisation's data, systems and ways of working against loss, misuse and interruption.
Like looking after a house - you lock the doors, check nothing has been tampered with, and make sure the family can still get in when they need to.
https://cmaintz.github.io/tech-atlas/en/terms/security/cyber-and-information-security/ atlas security fundamentals atlas-en-security/cyber-and-information-security
Cyber Resilience Act (CRA) The EU law that makes makers of connected products and software build them secure and keep fixing their flaws.
Like the safety rules for toys or kettles, but for the software inside things - a gadget that is easy to break into counts as unsafe to sell.
https://cmaintz.github.io/tech-atlas/en/terms/security/cyber-resilience-act/ atlas security compliance atlas-en-security/cyber-resilience-act
D-mærket A Danish label showing that a company takes care of IT security and data, starting with a free self-check.
Like the hygiene smiley on a restaurant door, but for how carefully a company treats the information and computers in its care.
https://cmaintz.github.io/tech-atlas/en/terms/security/d-maerket/ atlas security compliance atlas-en-security/d-maerket
Data breach An event where private information is seen, taken, changed or lost by people who should not have it.
Like a lost folder of patient records turning up on a train seat - whoever finds it can read it.
https://cmaintz.github.io/tech-atlas/en/terms/security/data-breach/ atlas security incident-response atlas-en-security/data-breach
Data classification Sorting data by how sensitive it is - for example public, internal or confidential.
Like sorting post into postcards, letters and registered mail - each is handled with a different level of care.
https://cmaintz.github.io/tech-atlas/en/terms/security/data-classification/ atlas security fundamentals atlas-en-security/data-classification
Data controller The organisation that decides why and how personal data is used, and so carries the main legal duty under GDPR.
Like someone who hires a moving firm - the movers carry the boxes, but you chose what to move and where, so it is on you if the wrong things end up in the wrong place.
https://cmaintz.github.io/tech-atlas/en/terms/security/data-controller/ atlas security compliance atlas-en-security/data-controller
Data ethics Asking not only whether a use of data is legal, but whether it is fair, open and in line with what people would expect.
The law is the speed limit; ethics is slowing down outside a school at home time even though the sign still says 50.
https://cmaintz.github.io/tech-atlas/en/terms/security/data-ethics/ atlas security compliance atlas-en-security/data-ethics
Data processing agreement (DPA) A written contract that sets how a supplier may handle personal data on your behalf.
Like the written rules you leave for a house-sitter - which rooms they may enter, who else may come in, and what to do if something goes missing.
https://cmaintz.github.io/tech-atlas/en/terms/security/data-processing-agreement/ atlas security compliance atlas-en-security/data-processing-agreement
Data processor An outside party that handles personal data on behalf of another organisation and only as that organisation instructs.
Like a laundry that washes a hotel's sheets - it takes good care of them and sends them back, but it has no say in what the hotel uses them for.
https://cmaintz.github.io/tech-atlas/en/terms/security/data-processor/ atlas security compliance atlas-en-security/data-processor
Defence in depth Stacking several independent layers of protection so that when one fails, the next one still stops the attacker.
Like protecting a home with a locked gate, a locked door, an alarm and a safe for the valuables - a thief who gets past one still meets the next.
https://cmaintz.github.io/tech-atlas/en/terms/security/defence-in-depth/ atlas security fundamentals atlas-en-security/defence-in-depth
Denial of service (DoS/DDoS) An attack that floods a website or service with so much traffic that real users can no longer reach it.
Thousands of fake customers crowding a shop's doorway so the real ones cannot get in.
https://cmaintz.github.io/tech-atlas/en/terms/security/denial-of-service/ atlas security fundamentals atlas-en-security/denial-of-service
Detection rule A written condition that a monitoring tool checks against incoming logs, raising an alarm whenever the events match it.
Like telling a shop guard exactly what to watch for - "anyone who tries three card terminals in a row" - instead of asking him to watch for anything strange.
https://cmaintz.github.io/tech-atlas/en/terms/security/detection-rule/ atlas security security-operations atlas-en-security/detection-rule
Disaster recovery plan (DRP) A technical plan for bringing data and systems back after a breakdown or attack, in a set order and time.
Like a rebuild guide for a house after a flood - which walls go up first, where the spare parts are, and how long each step takes.
https://cmaintz.github.io/tech-atlas/en/terms/security/disaster-recovery-plan/ atlas security incident-response atlas-en-security/disaster-recovery-plan
DORA The EU law that makes banks, insurers and other financial firms able to keep running through IT failures and cyber attacks.
Like fire rules that ask a bank not just to hang smoke alarms, but to prove in a drill that it can get everyone out, keep serving customers and tell the fire service what happened.
https://cmaintz.github.io/tech-atlas/en/terms/security/dora/ atlas security compliance atlas-en-security/dora
Data protection impact assessment (DPIA) A written check, done before starting, of how a planned use of personal data could harm people and how to reduce that harm.
Like an architect checking how a new building will affect the neighbours' light and noise before building starts, not after.
https://cmaintz.github.io/tech-atlas/en/terms/security/dpia/ atlas security compliance atlas-en-security/dpia
Endpoint detection and response (EDR) Software on each computer and phone that watches for signs of an attack and can stop it on the spot.
Like a guard posted inside every room of a building rather than only at the front door - they notice odd behaviour and can lock the room at once.
https://cmaintz.github.io/tech-atlas/en/terms/security/edr/ atlas security controls atlas-en-security/edr
Endpoint Any device that connects to the network at its edge and is used directly - a PC, phone, printer or similar.
Like the houses along a road system - the places the roads actually lead to, where people live and work, rather than the junctions in between.
https://cmaintz.github.io/tech-atlas/en/terms/security/endpoint/ atlas security cs controls atlas-en-security/endpoint
Escalation procedure Agreed rules for when a problem must be passed up to someone more senior or more expert, and to whom.
Like a hospital emergency room - a nurse handles small cuts, but chest pain goes straight to the senior doctor, and everyone knows the rule.
https://cmaintz.github.io/tech-atlas/en/terms/security/escalation-procedure/ atlas security incident-response atlas-en-security/escalation-procedure
EU directive A type of EU law that sets goals every member state must reach, but lets each country write its own national law to do it.
Like a parent telling several teenagers "your rooms must be clean by Sunday" - the goal is fixed, but each decides how to get there.
https://cmaintz.github.io/tech-atlas/en/terms/security/eu-directive/ atlas security compliance atlas-en-security/eu-directive
EU regulation A type of EU law that applies directly and identically in every member state, with no national law needed to bring it in.
Like a single book of rules for a chess tournament played in many countries - every table follows the same page, and no host country may print its own version.
https://cmaintz.github.io/tech-atlas/en/terms/security/eu-regulation/ atlas security compliance atlas-en-security/eu-regulation
Exploit A piece of code or a set of steps that turns a known weakness in a system into actual access or control for an attacker.
Like a bent piece of wire that someone has shaped to open one particular kind of cheap lock - it works every time, for anyone who copies the shape.
https://cmaintz.github.io/tech-atlas/en/terms/security/exploit/ atlas security fundamentals atlas-en-security/exploit
False positive An alarm about an attack or problem that turns out not to exist, because harmless activity was taken for harmful.
Like a car alarm that goes off every time a lorry drives past; after a week, nobody on the street even looks up.
https://cmaintz.github.io/tech-atlas/en/terms/security/false-positive/ atlas security security-operations atlas-en-security/false-positive
Gap analysis A comparison of what an organisation does today with the requirements it wants to meet.
Holding your half-packed suitcase against the packing list to see what you still need to buy before the trip.
https://cmaintz.github.io/tech-atlas/en/terms/security/gap-analysis/ atlas security compliance atlas-en-security/gap-analysis
GDPR The EU law that protects personal data and gives people rights over how it is used.
Information about you is treated as yours - others may borrow it only for a fair reason, must look after it and must tell you what they do with it.
https://cmaintz.github.io/tech-atlas/en/terms/security/gdpr/ atlas security compliance atlas-en-security/gdpr
Governance How leadership steers security - setting direction, handing out responsibility and checking that it works.
Like the captain of a ship - the crew does the rowing, but someone must choose the course and answer for where the ship ends up.
https://cmaintz.github.io/tech-atlas/en/terms/security/governance/ atlas security fundamentals atlas-en-security/governance
Governance, risk and compliance (GRC) The joined-up work of steering security from the top, deciding which dangers to handle, and proving that rules are met.
Like a school - the head sets the goals, the teachers spot which pupils are falling behind, and the outside examiner checks the results against the rules.
https://cmaintz.github.io/tech-atlas/en/terms/security/grc/ atlas security compliance atlas-en-security/grc
Grey roles Security jobs that sit between technology, management and people - coordinating and translating rather than hands-on engineering.
Like an interpreter at a meeting between two countries - not the expert on either side, but the reason the two sides understand each other.
https://cmaintz.github.io/tech-atlas/en/terms/security/grey-roles/ atlas security compliance atlas-en-security/grey-roles
Hardening Making a system harder to attack by turning off what is not needed and changing unsafe default settings.
Like moving into a new house and changing the locks, bricking up a door you never use and taking the spare key out from under the mat.
https://cmaintz.github.io/tech-atlas/en/terms/security/hardening/ atlas security controls atlas-en-security/hardening
Risk heat map A colour-coded grid that places each risk by how likely and how harmful it is, so the worst stand out in red.
Like a traffic light for dangers, showing at a glance which ones need action now and which can wait.
https://cmaintz.github.io/tech-atlas/en/terms/security/heat-map/ atlas security risk-management atlas-en-security/heat-map
Human error An honest mistake by a person - a wrong click, a lost laptop, a file sent to the wrong address - that harms security.
Like leaving the front door unlocked by accident - nobody planned a break-in, but the house is open all the same.
https://cmaintz.github.io/tech-atlas/en/terms/security/human-error/ atlas security fundamentals atlas-en-security/human-error
Human factor How people's habits, stress, trust and attention shape security - a common way in for attackers, but also a line of defence.
Like a road built for real drivers - tired, hurried and distracted - rather than for perfect ones; good safety plans for how people actually behave.
https://cmaintz.github.io/tech-atlas/en/terms/security/human-factor/ atlas security fundamentals atlas-en-security/human-factor
Human firewall A workforce that acts as the first line of defence by spotting and stopping attacks aimed at people.
Like a neighbourhood where everyone notices a stranger trying door handles and calls it in - the street itself becomes the alarm.
https://cmaintz.github.io/tech-atlas/en/terms/security/human-firewall/ atlas security awareness atlas-en-security/human-firewall
Impact How much harm an event would do to the business if it actually happened - in money, time, trust or safety.
Spilling coffee on a napkin and spilling it on your laptop are equally likely - but one hurts far more.
https://cmaintz.github.io/tech-atlas/en/terms/security/impact/ atlas security fundamentals atlas-en-security/impact
Incident reporting Telling the right people and authorities about a serious security event, quickly and within set deadlines.
Like calling the fire brigade and your neighbours as soon as you see smoke, rather than after the fire is out.
https://cmaintz.github.io/tech-atlas/en/terms/security/incident-reporting/ atlas security incident-response atlas-en-security/incident-reporting
Incident response The organised way a company spots, stops and cleans up after a security attack or accident, then gets back to normal.
Like a fire drill that turns into the real thing - everyone knows who calls for help, who closes the doors and who counts heads.
https://cmaintz.github.io/tech-atlas/en/terms/security/incident-response/ atlas security incident-response atlas-en-security/incident-response
Indicator of compromise (IoC) A trace left behind by an attack, such as a known bad web address or file, that shows a system has probably been broken into.
Like the footprints and a known burglar's tools found in a garden; they do not stop the break-in, but they tell you who has been there.
https://cmaintz.github.io/tech-atlas/en/terms/security/indicator-of-compromise/ atlas security security-operations atlas-en-security/indicator-of-compromise
Information security coordinator The person who keeps an organisation's day-to-day security work organised, tracked and reported to management.
Like a wedding planner - they do not cook, play music or take photos, but they make sure everyone who does shows up on time and knows the plan.
https://cmaintz.github.io/tech-atlas/en/terms/security/information-security-coordinator/ atlas security compliance atlas-en-security/information-security-coordinator
Input validation Checking every piece of data a program receives against strict rules before using it, and turning away anything that does not fit.
Like a post office that only accepts parcels of set sizes with a proper address on them, and hands everything else straight back across the counter.
https://cmaintz.github.io/tech-atlas/en/terms/security/input-validation/ atlas security application-security atlas-en-security/input-validation
Insider threat Harm that comes from someone already trusted inside the organisation, whether they mean to do damage or simply make a mistake.
Like a shop where the biggest losses come not from burglars but from staff - a few who slip goods into their bag, and many more who simply forget to lock up.
https://cmaintz.github.io/tech-atlas/en/terms/security/insider-threat/ atlas security fundamentals atlas-en-security/insider-threat
Integrity Making sure information stays correct and complete, and is not changed by accident or without permission.
Like a recipe card - if someone quietly changes “one teaspoon of salt” to “one cup”, everyone who follows it ruins the dish without knowing why.
https://cmaintz.github.io/tech-atlas/en/terms/security/integrity/ atlas security fundamentals atlas-en-security/integrity
Intrusion detection system (IDS) A watcher that inspects network traffic or a machine's activity and warns when it spots signs of an attack - without stopping it.
Like a burglar alarm - it rings when someone breaks in, but it does not lock the door.
https://cmaintz.github.io/tech-atlas/en/terms/security/intrusion-detection-system/ atlas security controls atlas-en-security/intrusion-detection-system
Intrusion prevention system (IPS) A guard placed in the path of network traffic that recognises signs of an attack and blocks them as they happen.
Like a bouncer at the door who turns away anyone matching a description, instead of just phoning the police.
https://cmaintz.github.io/tech-atlas/en/terms/security/intrusion-prevention-system/ atlas security controls atlas-en-security/intrusion-prevention-system
Information security management system (ISMS) The set of policies, roles, processes and records an organisation uses to run its information security in a planned, repeatable way.
Like the way a well-run restaurant kitchen works - not one recipe, but the routines for buying, storing, cooking, cleaning and checking that keep every meal safe, whoever is on shift.
https://cmaintz.github.io/tech-atlas/en/terms/security/isms/ atlas security compliance atlas-en-security/isms
ISO 27000 series The family of international standards for information security, with ISO 27001 at its centre and guides built around it.
Like the booklets that come with a new car - one lists what the car must meet to pass its inspection, and the others explain the brakes, the lights and the engine in detail.
https://cmaintz.github.io/tech-atlas/en/terms/security/iso-27000-series/ atlas security compliance atlas-en-security/iso-27000-series
ISO 27001 The international standard for running an information security management system that can be certified.
A set of house rules for running security as a daily routine rather than a one-off clean-up - written so that an outside inspector can check it is really followed.
https://cmaintz.github.io/tech-atlas/en/terms/security/iso-27001/ atlas security compliance atlas-en-security/iso-27001
ISO 27002 A guidance standard describing each security control in detail - what it is for and how to put it in place.
If the house rules say "keep the house safe", this is the handyman's manual explaining which locks, alarms and smoke detectors to fit and where.
https://cmaintz.github.io/tech-atlas/en/terms/security/iso-27002/ atlas security compliance atlas-en-security/iso-27002
IT operations The team and daily work that keep an organisation's computers, systems and networks running.
Like the ground crew at an airport - they refuel, load and check the planes so flights leave on time; the pilots are the ones people notice, but nothing moves without the crew.
https://cmaintz.github.io/tech-atlas/en/terms/security/it-operations/ atlas security fundamentals atlas-en-security/it-operations
Lateral movement What an attacker does after getting a first foothold - spreading from machine to machine inside the network.
A burglar who gets in through the garage and then walks freely through every unlocked door in the house.
https://cmaintz.github.io/tech-atlas/en/terms/security/lateral-movement/ atlas security fundamentals atlas-en-security/lateral-movement
Legacy system An old system the business still depends on but that can no longer be updated, replaced or protected in the normal way.
Like an old car whose maker went out of business - it still drives, but when something breaks there are no new parts.
https://cmaintz.github.io/tech-atlas/en/terms/security/legacy-system/ atlas security cs fundamentals atlas-en-security/legacy-system
Lessons learned Looking back after an incident or exercise to see what worked, what failed and what to change next time.
Like a football team watching the match again on video to see why they let in that goal.
https://cmaintz.github.io/tech-atlas/en/terms/security/lessons-learned/ atlas security incident-response atlas-en-security/lessons-learned
Likelihood How probable it is that a given threat will actually use a weakness and cause harm within a certain period.
Like a pot on the stove - if you walk away it will almost surely boil over; if you stand and watch, it hardly ever does.
https://cmaintz.github.io/tech-atlas/en/terms/security/likelihood/ atlas security fundamentals atlas-en-security/likelihood
Log management Collecting logs from every system into one place, in one format, kept safe from change and for as long as they are needed.
Like the archive at the town hall, which gathers the papers from every office, files them the same way, locks them up and throws them out on a fixed date.
https://cmaintz.github.io/tech-atlas/en/terms/security/log-management/ atlas security cs security-operations atlas-en-security/log-management
Log retention Deciding how long each kind of log is kept before it is deleted - long enough to look into incidents, but no longer than needed.
Like keeping till receipts; throw them out after a day and you cannot handle a return, keep them forever and the back room fills with paper about people who shopped years ago.
https://cmaintz.github.io/tech-atlas/en/terms/security/log-retention/ atlas security security-operations atlas-en-security/log-retention
Malware Harmful software that sneaks onto a computer or phone to steal, spy, damage or take control.
A stranger hiding in your house who reads your letters, copies your keys or quietly breaks things.
https://cmaintz.github.io/tech-atlas/en/terms/security/malware/ atlas security fundamentals atlas-en-security/malware
Man-in-the-middle attack An attacker secretly placed between two parties who reads or changes their messages while each believes they talk directly.
Like a postman who steams open your letters, reads them, maybe changes a line, and seals them again before delivery - neither you nor your friend notice.
https://cmaintz.github.io/tech-atlas/en/terms/security/man-in-the-middle/ atlas security fundamentals atlas-en-security/man-in-the-middle
Management responsibility The duty of top leaders to own, approve and be able to show the organisation's security work.
The captain answers for the ship - the crew may do the work, but when it hits the rocks the captain cannot say "that was not my job".
https://cmaintz.github.io/tech-atlas/en/terms/security/management-responsibility/ atlas security compliance atlas-en-security/management-responsibility
Multi-factor authentication A way to log in that asks for two or more separate kinds of proof, such as a password plus a code or an approval in a phone app.
Like a safe-deposit box that needs both your key and your signature - a thief who copies one still cannot open it.
https://cmaintz.github.io/tech-atlas/en/terms/security/mfa/ atlas security controls atlas-en-security/mfa
MITRE ATT&CK A free, public catalogue of the goals and methods real attackers use, giving defenders a shared language for how attacks unfold.
Like a handbook of every trick known to pickpockets, sorted by stage - picking a victim, distracting them, taking the wallet, getting away - so guards know what to watch for at each step.
https://cmaintz.github.io/tech-atlas/en/terms/security/mitre-attack/ atlas security security-operations atlas-en-security/mitre-attack
NIS1 Directive The first EU-wide cybersecurity law, from 2016, which set security and reporting duties for key service providers until NIS2 replaced it.
Like the first edition of a book of rules - it set the idea that firms society leans on must guard their systems, but left each country free to decide who had to follow it.
https://cmaintz.github.io/tech-atlas/en/terms/security/nis1/ atlas security compliance atlas-en-security/nis1
NIS2 Directive The EU cybersecurity law that sets shared security duties for organisations in important and critical sectors.
Like common building safety rules for the whole EU - every country must write them into its own law, and those who keep society running must build by them.
https://cmaintz.github.io/tech-atlas/en/terms/security/nis2/ atlas security compliance atlas-en-security/nis2
Essential and important entities (NIS2) The two groups of organisations NIS2 covers, sorted by sector and size, with stricter oversight for the essential group.
Like road rules for lorries and vans - both must drive safely, but lorries are pulled over for checks more often because a crash does more harm.
https://cmaintz.github.io/tech-atlas/en/terms/security/nis2-entities/ atlas security compliance atlas-en-security/nis2-entities
Danish NIS2 Act (NIS2-loven) The Danish law that writes the EU's NIS2 rules into national law and names who checks that firms follow them.
The EU writes the recipe, but each country bakes its own cake - this is the Danish one, with Danish inspectors tasting it.
https://cmaintz.github.io/tech-atlas/en/terms/security/nis2-loven/ atlas security compliance atlas-en-security/nis2-loven
NIS2 minimum requirements The baseline list of security measures every organisation under NIS2 must have in place.
Like the equipment every car must have before it may use the road - lights, brakes, seat belts - however big or small the car.
https://cmaintz.github.io/tech-atlas/en/terms/security/nis2-minimum-requirements/ atlas security compliance atlas-en-security/nis2-minimum-requirements
NIST Cybersecurity Framework (CSF) A free US framework that sorts security work into six broad goals, from steering it to recovering after an attack.
A map with six regions rather than a checklist - it shows where you are, where you want to be and which roads connect them, but not exactly how to drive.
https://cmaintz.github.io/tech-atlas/en/terms/security/nist-csf/ atlas security compliance atlas-en-security/nist-csf
Non-repudiation Proof of who did something that is strong enough that they cannot later deny having done it.
Like signing for a parcel in front of a witness - you cannot later claim it never came, and the courier cannot claim to have left it with you if they did not.
https://cmaintz.github.io/tech-atlas/en/terms/security/non-repudiation/ atlas security fundamentals atlas-en-security/non-repudiation
Nudging Small, gentle prompts that make the safe choice the easy one, without forbidding anything.
Like painting footsteps on the floor leading to the stairs - nobody is forced, but most people follow them.
https://cmaintz.github.io/tech-atlas/en/terms/security/nudging/ atlas security awareness atlas-en-security/nudging
One-time password (OTP) A short code that works for a single login and then expires, sent by text message or shown in an app.
Like a ticket that is torn in half at the door - it gets you in once, and a copy is worth nothing afterwards.
https://cmaintz.github.io/tech-atlas/en/terms/security/one-time-password/ atlas security cs controls atlas-en-security/one-time-password
Organisational control A safeguard made of rules, roles and routines - who decides, who does what, and how work must be done.
Like the plan for a school trip - the teacher counts heads at every stop, children walk in pairs, and nobody leaves the group without telling an adult. No fence is needed.
https://cmaintz.github.io/tech-atlas/en/terms/security/organisational-control/ atlas security controls atlas-en-security/organisational-control
OWASP Top 10 A widely used, regularly updated list of the ten most serious kinds of security flaw found in web applications.
Like a motoring group's list of the ten faults most often found in used cars - not every possible fault, but the ones worth checking first.
https://cmaintz.github.io/tech-atlas/en/terms/security/owasp-top-10/ atlas security application-security atlas-en-security/owasp-top-10
Patch management The routine of keeping all software up to date so that known weaknesses are closed before attackers use them.
Like a car recall - the fault is known and a fix exists, but it only helps once each car is actually brought in.
https://cmaintz.github.io/tech-atlas/en/terms/security/patch-management/ atlas security controls atlas-en-security/patch-management
Continuous improvement (PDCA) A repeating four-step loop - Plan, Do, Check, Act - for getting a little better each round.
Like a cook perfecting a dish - make it, taste it, adjust the seasoning, and cook it again next week a little better.
https://cmaintz.github.io/tech-atlas/en/terms/security/pdca/ atlas security compliance atlas-en-security/pdca
Penetration test An agreed, simulated attack in which skilled testers try to break in, to show how well systems really hold up.
Like hiring a professional burglar to try to break into your shop, with your permission, and then write down exactly how they got in.
https://cmaintz.github.io/tech-atlas/en/terms/security/penetration-test/ atlas security controls atlas-en-security/penetration-test
People control A safeguard aimed at staff themselves - screening, training, clear duties and what happens when someone joins or leaves.
Like a kindergarten that checks a new helper's background, walks her through the daily routines on her first day and takes back her key when she leaves - the safety comes from who is let in and what they know.
https://cmaintz.github.io/tech-atlas/en/terms/security/people-control/ atlas security controls atlas-en-security/people-control
Perimeter security Guarding the edge between an organisation's own network and the outside world, and trusting what is already inside.
A castle with thick walls and one guarded gate - once you are past the gate, you can walk into almost any room.
https://cmaintz.github.io/tech-atlas/en/terms/security/perimeter-security/ atlas security fundamentals atlas-en-security/perimeter-security
Personal data Any information about a living person who can be named or traced, directly or by putting pieces together.
Anything that points to you - not just your name, but your number plate, your face on a camera or the fact that "the only redhead on the third floor" called in sick.
https://cmaintz.github.io/tech-atlas/en/terms/security/personal-data/ atlas security compliance atlas-en-security/personal-data
Phishing Fake emails or messages sent in bulk to trick people into handing over information or clicking something harmful.
Like casting a net with bait into the sea - the sender does not care which fish bites, only that some do.
https://cmaintz.github.io/tech-atlas/en/terms/security/phishing/ atlas security awareness atlas-en-security/phishing
Phishing simulation Sending staff harmless fake phishing mails to see who clicks and to teach them to spot the real thing.
Like a fire drill for the inbox - practising the right reaction while nothing is really burning.
https://cmaintz.github.io/tech-atlas/en/terms/security/phishing-simulation/ atlas security awareness atlas-en-security/phishing-simulation
Physical security Protecting buildings, rooms and equipment so that nobody can simply walk in, take, break or plug into them.
The best lock on a diary is no help if someone can simply pick up the whole diary and walk off with it.
https://cmaintz.github.io/tech-atlas/en/terms/security/physical-security/ atlas security fundamentals atlas-en-security/physical-security
Pretexting Inventing a believable cover story and role, such as a new colleague or an auditor, to get someone to share information.
Like an actor who turns up in a delivery uniform with a clipboard - nobody asks questions, because the costume and the story fit.
https://cmaintz.github.io/tech-atlas/en/terms/security/pretexting/ atlas security awareness atlas-en-security/pretexting
Privacy by design The GDPR principle that protection of personal data must be built into systems from the start.
Drawing curtains into the plans for a new house, rather than taping newspaper over the windows after moving in.
https://cmaintz.github.io/tech-atlas/en/terms/security/privacy-by-design/ atlas security compliance atlas-en-security/privacy-by-design
Privilege escalation An attacker who has a small foothold gaining more rights than they were given, up to full control of the system.
Like a hotel guest whose card opens only one room, who finds a way to turn it into the manager's master key.
https://cmaintz.github.io/tech-atlas/en/terms/security/privilege-escalation/ atlas security fundamentals atlas-en-security/privilege-escalation
Qualitative risk analysis Rating risks with words or simple scales, such as low, medium and high, based on judgement rather than exact figures.
Like a mountain guide calling a slope "probably fine, but deadly if it slides" - quick and useful, even without an exact percentage.
https://cmaintz.github.io/tech-atlas/en/terms/security/qualitative-risk-analysis/ atlas security risk-management atlas-en-security/qualitative-risk-analysis
Quantitative risk analysis Putting numbers on risks - how often a loss may happen and how much it would cost - to compare them in money.
Like deciding on an extended warranty for a washing machine - if a repair costs 2,000 and is needed once in five years, paying 800 a year for the warranty is a bad deal.
https://cmaintz.github.io/tech-atlas/en/terms/security/quantitative-risk-analysis/ atlas security risk-management atlas-en-security/quantitative-risk-analysis
Ransomware Harmful software that locks an organisation's data and demands payment to unlock it.
Like a burglar who takes nothing but changes all the locks in your house and sells you the new keys.
https://cmaintz.github.io/tech-atlas/en/terms/security/ransomware/ atlas security awareness atlas-en-security/ransomware
Recovery objectives (RTO/RPO) Two agreed limits for a failure - how long a system may be down (RTO) and how much recent data may be lost (RPO).
If your phone dies, RTO is how long you can manage without one; RPO is how many days of photos you could stand to lose since your last copy.
https://cmaintz.github.io/tech-atlas/en/terms/security/recovery-objectives/ atlas security incident-response atlas-en-security/recovery-objectives
Residual risk The risk still left after controls are in place, because no protection removes danger completely.
Even with a seat belt, driving still carries some chance of getting hurt.
https://cmaintz.github.io/tech-atlas/en/terms/security/residual-risk/ atlas security risk-management atlas-en-security/residual-risk
Risk How likely it is that a threat uses a vulnerability, combined with how bad the damage would be.
Like deciding whether to insure a bike - you weigh how often bikes get stolen round here against how much a new one would cost.
https://cmaintz.github.io/tech-atlas/en/terms/security/risk/ atlas security fundamentals atlas-en-security/risk
Risk acceptance A deliberate, recorded decision to live with a risk instead of spending more to reduce it.
Like driving on with a small chip at the edge of the windscreen - you note it, decide a new glass is not worth it yet, and look at it again after the winter.
https://cmaintz.github.io/tech-atlas/en/terms/security/risk-acceptance/ atlas security risk-management atlas-en-security/risk-acceptance
Risk appetite How much risk leadership is willing to live with to reach the company's goals.
Like how fast you are willing to drive - some people accept more danger to arrive sooner, others do not.
https://cmaintz.github.io/tech-atlas/en/terms/security/risk-appetite/ atlas security risk-management atlas-en-security/risk-appetite
Risk assessment Working out what could go wrong, how likely it is and how much harm it would do, so the biggest risks get handled first.
Before a picnic you ask what could spoil it, how likely that is and how bad it would be - then you bring an umbrella rather than worrying about bears.
https://cmaintz.github.io/tech-atlas/en/terms/security/risk-assessment/ atlas security risk-management atlas-en-security/risk-assessment
Risk avoidance Removing a risk entirely by not doing, or no longer doing, the activity that creates it.
Like selling the trampoline because the children keep getting hurt - no more jumping, but also no more broken arms.
https://cmaintz.github.io/tech-atlas/en/terms/security/risk-avoidance/ atlas security risk-management atlas-en-security/risk-avoidance
Risk identification The first step of a risk assessment - finding and writing down what could go wrong, to what, and why.
Like walking through a new flat before moving in and noting every loose wire, wobbly step and window that does not close - fixing comes later.
https://cmaintz.github.io/tech-atlas/en/terms/security/risk-identification/ atlas security risk-management atlas-en-security/risk-identification
Risk management The ongoing work of finding, weighing and handling risks so that time and money go where they protect the most.
Like a household deciding which locks, insurance and smoke alarms are worth paying for, instead of buying everything or nothing.
https://cmaintz.github.io/tech-atlas/en/terms/security/risk-management/ atlas security risk-management atlas-en-security/risk-management
Risk mitigation Lowering a risk by adding controls that make it less likely to happen or less harmful if it does.
Like putting a rubber mat in the shower and a grab bar by the bath - you still wash, but a fall is less likely and less bad if it happens.
https://cmaintz.github.io/tech-atlas/en/terms/security/risk-mitigation/ atlas security risk-management atlas-en-security/risk-mitigation
Risk monitoring Keeping an eye on known risks over time, so changes are caught and decisions are revisited before they go stale.
Like a gardener walking round the beds every week - the planting was planned in spring, but pests, frost and dry spells keep changing what needs doing.
https://cmaintz.github.io/tech-atlas/en/terms/security/risk-monitoring/ atlas security risk-management atlas-en-security/risk-monitoring
Risk profile The overall picture of which dangers an organisation faces and how serious they are, given its size, sector, data and systems.
Like packing for a trip - a week of camping by the sea and a weekend in a city hotel call for very different bags, even for the same traveller.
https://cmaintz.github.io/tech-atlas/en/terms/security/risk-profile/ atlas security risk-management atlas-en-security/risk-profile
Risk transfer Moving the financial cost of a risk to another party, usually through insurance or a contract with a supplier.
Like hiring a removal firm that pays if it drops your piano - you get the money back, but you still have no piano for the party on Saturday.
https://cmaintz.github.io/tech-atlas/en/terms/security/risk-transfer/ atlas security risk-management atlas-en-security/risk-transfer
Risk treatment Choosing what to do about each risk - accept it, reduce it, share it with someone else, or avoid it altogether.
Like facing a leaky roof - you can live with it, patch it, buy insurance, or move out.
https://cmaintz.github.io/tech-atlas/en/terms/security/risk-treatment/ atlas security risk-management atlas-en-security/risk-treatment
Secure development lifecycle (SDL) A fixed set of security steps built into every stage of making software, from planning and design through testing to release.
Like the checks a new building must pass at each stage - drawings approved, foundation inspected, wiring tested - instead of one inspection when it is already finished.
https://cmaintz.github.io/tech-atlas/en/terms/security/secure-development-lifecycle/ atlas security application-security atlas-en-security/secure-development-lifecycle
Security awareness What staff know about security and how they act on it in daily work.
Like teaching everyone in a building where the fire exits are and why the fire doors must stay shut - knowing is only half of it; doing it every day is the point.
https://cmaintz.github.io/tech-atlas/en/terms/security/security-awareness/ atlas security awareness atlas-en-security/security-awareness
Security by design Thinking security into systems and processes from the very start, instead of adding it at the end.
Like planning the wiring before the walls go up - doing it later means tearing down walls.
https://cmaintz.github.io/tech-atlas/en/terms/security/security-by-design/ atlas security fundamentals atlas-en-security/security-by-design
Security culture The shared habits and attitudes toward security that shape how people act when nobody is checking.
Like the difference between a kitchen where everyone washes their hands because “that's just how we do it” and one where people only do it when the boss is watching.
https://cmaintz.github.io/tech-atlas/en/terms/security/security-culture/ atlas security awareness atlas-en-security/security-culture
Security framework A ready-made, shared structure of goals and controls that an organisation follows to build and check its security work.
A well-tested cookbook - you do not invent the dish from scratch, you follow proven steps and adjust to taste.
https://cmaintz.github.io/tech-atlas/en/terms/security/security-framework/ atlas security compliance atlas-en-security/security-framework
Security incident An event that has harmed, or may soon harm, the confidentiality, integrity or availability of information or systems.
Not the storm warning on the radio, but the water now dripping through the ceiling - something is already wrong, and someone has to act.
https://cmaintz.github.io/tech-atlas/en/terms/security/security-incident/ atlas security fundamentals atlas-en-security/security-incident
Security maturity How far an organisation's security has grown - from random and tied to single people to planned, measured and steadily improving.
Like belt colours in karate - they show not whether you can win one fight, but how steady and practised your skills have become.
https://cmaintz.github.io/tech-atlas/en/terms/security/security-maturity/ atlas security compliance atlas-en-security/security-maturity
Security metrics (KPIs) Numbers chosen in advance to show whether security work is having the effect it should.
Like a bathroom scale on a diet - not the goal itself, but the honest number that tells you whether what you are doing is working.
https://cmaintz.github.io/tech-atlas/en/terms/security/security-metrics/ atlas security compliance atlas-en-security/security-metrics
Security monitoring Keeping a steady watch on systems and networks so that signs of attack or misuse are spotted while there is still time to act.
Like a night watchman walking the same rounds every hour - not to stop every break-in on the spot, but to notice the broken window before morning.
https://cmaintz.github.io/tech-atlas/en/terms/security/security-monitoring/ atlas security controls atlas-en-security/security-monitoring
Security policy A document that sets out an organisation's goals, responsibilities and principles for information security.
Like the house rules on a fridge - short, agreed by the grown-ups, and meant to settle arguments before they start.
https://cmaintz.github.io/tech-atlas/en/terms/security/security-policy/ atlas security fundamentals atlas-en-security/security-policy
Self-assessment An organisation checking its own security against a set list of questions or criteria, without an outside inspector.
Like going through a home safety checklist on a Sunday - you walk round with the list yourself to see what needs fixing, before anyone official ever comes by.
https://cmaintz.github.io/tech-atlas/en/terms/security/self-assessment/ atlas security compliance atlas-en-security/self-assessment
Session hijacking Taking over someone's session after they have logged in, so the attacker is treated as that user without knowing the password.
Someone copies the stamp on your hand outside the club and walks in as if they had shown ID at the door.
https://cmaintz.github.io/tech-atlas/en/terms/security/session-hijacking/ atlas security fundamentals atlas-en-security/session-hijacking
Shadow IT Apps and tools staff use for work without the IT department knowing about or approving them.
Like tenants quietly adding their own extension cords and heaters - it solves their problem, but the landlord has no idea the fire risk exists.
https://cmaintz.github.io/tech-atlas/en/terms/security/shadow-it/ atlas security awareness atlas-en-security/shadow-it
SIEM A system that gathers logs from across the organisation in one place and raises an alarm when something looks wrong.
Like a security guard's desk with screens from every camera in the building, plus a helper who points out when the same stranger shows up at three doors.
https://cmaintz.github.io/tech-atlas/en/terms/security/siem/ atlas security controls atlas-en-security/siem
Smishing Phishing sent as a text message, usually a short, urgent note with a link or a number to call.
Like a fake parking ticket tucked under your wiper - it looks official enough that you pay before you check.
https://cmaintz.github.io/tech-atlas/en/terms/security/smishing/ atlas security awareness atlas-en-security/smishing
SOAR A platform that ties a security team's tools together and runs the routine steps of handling an alarm by itself.
Like a kitchen where the prep cook does all the chopping and measuring from the recipe, so the chef only has to make the real decisions.
https://cmaintz.github.io/tech-atlas/en/terms/security/soar/ atlas security security-operations atlas-en-security/soar
Security operations centre (SOC) A team that watches an organisation's systems around the clock and acts when an alarm points to a real attack.
Like the control room of a fire service - people who never sleep, watch every call that comes in, and decide which ones need a truck right now.
https://cmaintz.github.io/tech-atlas/en/terms/security/soc/ atlas security controls atlas-en-security/soc
Social engineering Manipulating people into giving away information or access, instead of breaking into systems directly.
Like a con artist who does not pick the lock but simply talks the doorman into holding the door open.
https://cmaintz.github.io/tech-atlas/en/terms/security/social-engineering/ atlas security awareness atlas-en-security/social-engineering
Spear phishing A phishing message tailored to one person or team, made to look like it comes from someone they know.
Like a fisher who ignores the shoal and aims a spear at one particular fish, after watching where it likes to swim.
https://cmaintz.github.io/tech-atlas/en/terms/security/spear-phishing/ atlas security awareness atlas-en-security/spear-phishing
SQL injection An attack where text typed into a form is read by the database as a command, letting an outsider read or change its data.
Like a form that says "Pay the sum of ___ to Anna", where someone writes "10 kroner, and also pay everything to me" in the blank - and the clerk simply does all of it.
https://cmaintz.github.io/tech-atlas/en/terms/security/sql-injection/ atlas security application-security atlas-en-security/sql-injection
Statement of Applicability (SoA) A document listing every control in the ISO 27001 annex, saying whether each is used, and giving the reason.
Like a builder answering the fire officer's checklist item by item - installed, or not needed and why, such as “no sprinklers - one floor only, with two exits”.
https://cmaintz.github.io/tech-atlas/en/terms/security/statement-of-applicability/ atlas security compliance atlas-en-security/statement-of-applicability
STRIDE A memory aid that sorts threats into six kinds, so a team checks every part of a design for each kind in turn.
Like a pilot's pre-flight checklist - rather than trusting memory, you go down the same six questions every time so nothing obvious is skipped.
https://cmaintz.github.io/tech-atlas/en/terms/security/stride/ atlas security application-security atlas-en-security/stride
Supervisory authority The public body in each EU country that oversees GDPR, handles complaints and can seek fines; in Denmark, Datatilsynet.
Like the food inspector who can turn up at any restaurant, ask to see the fridge, order a clean-up and, if nothing changes, take the owner to court.
https://cmaintz.github.io/tech-atlas/en/terms/security/supervisory-authority/ atlas security compliance atlas-en-security/supervisory-authority
Supplier management Making sure outside partners who handle your data or systems meet your security demands.
You lock your own front door, but you also check that the cleaning company holding a spare key looks after it properly.
https://cmaintz.github.io/tech-atlas/en/terms/security/supplier-management/ atlas security compliance atlas-en-security/supplier-management
Supply chain attack Breaking into many targets at once by first taking over a supplier, product or update they all trust.
Like poisoning the flour at the mill instead of breaking into every bakery - each baker uses it in good faith.
https://cmaintz.github.io/tech-atlas/en/terms/security/supply-chain-attack/ atlas security fundamentals atlas-en-security/supply-chain-attack
Table-top exercise A practice session around a table where a team talks through a made-up crisis step by step to test its plans.
Like a football team walking through a set play on a board before trying it on the pitch.
https://cmaintz.github.io/tech-atlas/en/terms/security/table-top-exercise/ atlas security incident-response atlas-en-security/table-top-exercise
Technical control A safeguard built into hardware or software, which works automatically once it is set up.
Like the automatic lock on a car that clicks shut when you walk away - it protects you whether or not you remember.
https://cmaintz.github.io/tech-atlas/en/terms/security/technical-control/ atlas security controls atlas-en-security/technical-control
Threat Anything that could harm the organisation - an attacker, a careless mistake, a fire or a power cut.
Like a burglar in the neighbourhood or a storm in the forecast - it has not hurt you yet, but it could.
https://cmaintz.github.io/tech-atlas/en/terms/security/threat/ atlas security fundamentals atlas-en-security/threat
Threat actor The person or group behind an attack, such as a criminal gang, a foreign state, an activist or a careless insider.
Knowing that bikes get stolen in your area is one thing; knowing it is the same two teenagers every Friday night tells you when and how to lock up.
https://cmaintz.github.io/tech-atlas/en/terms/security/threat-actor/ atlas security fundamentals atlas-en-security/threat-actor
Threat hunting Searching on purpose for attackers who may already be inside the network, without waiting for an alarm to go off.
Like a store detective who walks the floor looking for known tricks, instead of only waiting for the alarm at the door to beep.
https://cmaintz.github.io/tech-atlas/en/terms/security/threat-hunting/ atlas security security-operations atlas-en-security/threat-hunting
Threat intelligence Up-to-date knowledge about current attackers and their methods, gathered so attacks can be stopped before they land.
Like neighbours warning each other that burglars are trying car doors on the street tonight.
https://cmaintz.github.io/tech-atlas/en/terms/security/threat-intelligence/ atlas security risk-management atlas-en-security/threat-intelligence
Threat landscape A picture of the kinds of threats a company could face right now, and who or what is behind them.
Like a weather forecast for danger, telling you whether to expect rain, storms or a heat wave in the weeks ahead.
https://cmaintz.github.io/tech-atlas/en/terms/security/threat-landscape/ atlas security risk-management atlas-en-security/threat-landscape
Threat modelling Sitting down with a drawing of a system to work out what could go wrong, who might cause it and what to do about it.
Like walking through the plans for a new house and asking at every door and window how someone could get in there, and what would stop them.
https://cmaintz.github.io/tech-atlas/en/terms/security/threat-modelling/ atlas security application-security atlas-en-security/threat-modelling
Two-factor authentication The most common form of MFA, where logging in needs exactly two separate proofs, usually a password and a one-time code.
Like a door with two different locks - one opened by what you remember, one by what is in your pocket.
https://cmaintz.github.io/tech-atlas/en/terms/security/two-factor-authentication/ atlas security controls atlas-en-security/two-factor-authentication
Vishing Tricking people over the phone or a voice call into giving away information, codes or money.
Like a smooth-talking salesman on the phone who never lets you pause long enough to think.
https://cmaintz.github.io/tech-atlas/en/terms/security/vishing/ atlas security awareness atlas-en-security/vishing
Vulnerability A weakness that a threat can use to cause harm.
Like a window left open or a lock that is easy to pick - nothing bad has happened, but the way in is there.
https://cmaintz.github.io/tech-atlas/en/terms/security/vulnerability/ atlas security fundamentals atlas-en-security/vulnerability
Vulnerability assessment A review of systems to find their weaknesses and rank which ones matter most to fix first.
Like a surveyor's report on a house - it lists every crack and leak, then tells you which ones will bring the roof down and which can wait.
https://cmaintz.github.io/tech-atlas/en/terms/security/vulnerability-assessment/ atlas security controls atlas-en-security/vulnerability-assessment
Vulnerability scanning An automatic, repeated check of systems against a list of known weaknesses, producing a report of what was found.
Like a mechanic plugging a reader into your car that lists every known fault code - quick and thorough, but it only finds problems already on its list.
https://cmaintz.github.io/tech-atlas/en/terms/security/vulnerability-scanning/ atlas security controls atlas-en-security/vulnerability-scanning
Web application firewall (WAF) A filter in front of a website that reads each web request and blocks those that look like known attacks.
Like a receptionist who opens every letter to a company and throws out the ones with a known scam inside, whereas an ordinary guard only checks the address on the envelope.
https://cmaintz.github.io/tech-atlas/en/terms/security/web-application-firewall/ atlas security cs application-security atlas-en-security/web-application-firewall
Zero-day vulnerability A flaw that attackers know about before the maker does, so on the day it is used there is no fix to install.
Like a burglar who has found a secret gap in the fence that even the owner does not know about - no lock can be fitted to a hole nobody has seen.
https://cmaintz.github.io/tech-atlas/en/terms/security/zero-day/ atlas security fundamentals atlas-en-security/zero-day
Zero Trust A security principle of never trusting anyone automatically - every request is checked, even from inside the network.
Like a hospital where your badge is checked at every ward door, not just at the main entrance - getting inside the building does not get you everywhere.
https://cmaintz.github.io/tech-atlas/en/terms/security/zero-trust/ atlas security controls atlas-en-security/zero-trust