All terms A-Z

435 terms, alphabetically.

A

Access control · Identity & access - The rules and mechanisms that decide who may use which systems, data or rooms, and in what way.
Access management · Controls & technical basics - The rules and routines that decide who may use which data and systems, and that keep those rights correct over time.
Accuracy · Evaluation & metrics - 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.
Activation function · Machine learning basics - The rule each unit in a neural network applies to its summed input, letting the network learn curved rather than straight patterns.
Adversarial example · AI risk & governance - An input altered on purpose, often in ways people cannot see, so that a trained AI model gives a confident but wrong answer.
Agent instructions file · AI-assisted coding - A plain text file kept with the code that tells AI tools the project's rules, commands and habits before they start work.
Agent memory · Agents & tools - 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.
Agent sandbox · Agents & tools - 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.
Agent2Agent protocol (A2A) · Agents & tools - An open standard that lets AI agents built by different companies find each other, hand over tasks and share results.
Agentic workflow · Agents & tools - A fixed chain of steps written in code, where a language model does some of the steps but does not choose the order.
AI agent · Language models - 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.
AI alignment · AI risk & governance - The work of making an AI system aim for what people actually intend, and refuse what they would not accept.
AI bias · AI risk & governance - When an AI system treats some people or cases unfairly because of one-sided data or design choices.
AI code review · AI-assisted coding - Using a large language model to read proposed code changes and leave comments on bugs, risks and style before a person approves them.
AI coding assistant · AI-assisted coding - A tool built into a programmer's editor that suggests, explains and rewrites code using a large language model.
AI governance · AI risk & governance - The rules, roles and checks an organisation uses to decide which AI it uses and to keep that use safe, lawful and fair.
AI pair programming · AI-assisted coding - Writing code together with an AI tool in a running back-and-forth, where the human stays in charge and checks every change.
AI red teaming · AI risk & governance - Testers attack an AI system on purpose, before and after release, to find ways it can be tricked into harmful or unsafe behaviour.
AI supply chain attack · AI risk & governance - Attacking the ready-made parts an AI system is built from - shared models, datasets or plug-in files - instead of the system itself.
Alert triage · Detection & response - Sorting incoming alarms quickly into real threats, harmless noise and cases that need a closer look, so the worst get handled first.
Alerting · Observability - Rules that tell the right person, at once, when a system needs human attention, and stay quiet when it does not.
Anomaly detection · Detection & response - Learning what normal activity looks like and raising an alarm when something departs from it, even if no rule describes the attack.
API · Web & data - A fixed set of requests one program offers so other programs can use its data or features without seeing its insides.
API security · Application 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.
Artificial intelligence (AI) · Machine learning basics - Computer systems that do tasks we normally link to human thinking, such as spotting patterns, answering questions or making choices.
Asset · Fundamentals - Anything of value to the organisation that needs protecting - data, systems, devices, people or know-how.
Asset inventory · Controls & technical basics - One complete, up-to-date list of the organisation's computers, devices, systems and software.
Attack surface · Application security - The sum of all the places where an outsider could try to get into a system, send data into it or pull data out.
Attention mechanism · Model architectures - The step inside a model that decides, for each token, which other tokens in the input matter most right now.
Audit · Compliance & regulation - An independent check of whether an organisation actually follows its own policies and the requirements it has signed up to.
Audit logging · Operating systems - A system's record of who did what, and when, for the actions that matter to security.
Authentication · Identity & access - Checking that someone who logs in really is who they claim to be, usually by asking for a credential such as a password.
Authentication factor · Controls & technical basics - One kind of proof used to log in - something you know, something you have, or something you are.
Authorization · Identity & access - Deciding what an already identified user is allowed to do, such as which files they may open or change.
Availability · Fundamentals - Making sure information and systems can be used by the right people when they are needed.
Awareness maturity · People, culture & awareness - A measure of how far an organisation has come in making security part of how its people think and act.
Awareness officer · People, culture & awareness - The person responsible for teaching staff to spot and avoid attacks, and for measuring whether their habits actually change.
Awareness programme · People, culture & awareness - A planned, ongoing effort to change how staff behave around security - with target groups, messages, methods and measurable goals.

B

Backpropagation · Training & optimisation - The bookkeeping method that works out, layer by layer from the output back, how much each weight in a network added to its mistake.
Backup · Controls & technical basics - A separate copy of data kept so it can be restored after a breakdown, a mistake or an attack.
Batch size · Training & optimisation - How many examples a model looks at together before it updates itself once during model training.
Benchmark · Evaluation & metrics - A shared, public set of tasks with a fixed way of scoring, so that different models can be compared on the same terms.
Bias-variance trade-off · Machine learning basics - The tension between a model too simple to catch the real pattern and one so flexible that it chases chance details in its examples.
Business continuity plan (BCP) · Incidents & continuity - A plan for keeping the most important work going during and after a crisis, even while the systems are down.
Business email compromise (CEO fraud) · People, culture & awareness - A scam where criminals pose as a boss or supplier by email to trick staff into paying money or sending data.
Business impact analysis (BIA) · Risk management - A study of what an outage or incident would do to the business, and how long each activity can be down.

C

Centre for Cyber Security (CFCS) · Compliance & regulation - Denmark's national cyber security body from 2012, which in January 2025 became part of the Danish Resilience Agency (SAMSIK).
CER Directive · Compliance & regulation - The EU law that makes the operators of vital services like power and water able to withstand floods, sabotage and other physical threats.
Certificate authority (CA) · Cryptography - A trusted body that checks who someone is and then signs digital certificates vouching that a public key belongs to them.
Certification · Compliance & regulation - Formal proof from an approved outside body that an organisation's security meets a published standard such as ISO 27001.
Chain-of-thought (CoT) · Prompting & generation - Getting a language model to write out its steps before the final answer, which tends to help on sums, logic and planning.
Change management · Controls & technical basics - A controlled process to plan, approve, record and check every change made to IT systems.
Chunking · Retrieval & search - Cutting long documents into smaller passages before storing them, so a search can return just the part that answers a question.
CI/CD · Software delivery - Merging, testing and releasing small software changes automatically and often, instead of in rare, large batches.
CIA triad · Fundamentals - The three pillars of information security - confidentiality, integrity and availability.
CIS Controls · Controls & technical basics - A ranked, public list of security measures from the Center for Internet Security that tells an organisation what to do first.
Classification · Machine learning basics - 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.
Client · Networking - The program or device that starts a network exchange by sending a request, such as a web browser asking for a page.
Cloud computing · Cloud - Renting computing power, storage and software over the internet from a provider, paying for what you use instead of owning it.
Cloud IAM · Cloud - The cloud provider's built-in system of policies that decides which users, roles and service accounts may do what to each resource.
Cloud misconfiguration · Cloud - A wrong or careless setting in a cloud service - like storage left open to everyone - that exposes data or systems.
Clustering · Machine learning basics - Letting a computer put similar items into groups by itself, with no names or right answers given in advance.
Code completion · AI-assisted coding - Greyed-out code that appears as you type, predicting the next line or block so you can accept it with one key.
Code signing · Software delivery - Adding a digital signature to software so users and systems can check who made it and that nobody changed it afterwards.
Coding agent · AI-assisted coding - An AI that is given a programming task and carries it out itself - reading files, running commands and editing code until done.
Communication plan · Incidents & continuity - A plan for who tells what to whom during a crisis - staff, customers, authorities and the press.
Compliance · Fundamentals - Living up to the laws, rules and standards that apply - for example NIS2, GDPR or ISO 27001.
Compliance and risk coordinator · Compliance & regulation - 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.
Compliance roadmap · Compliance & regulation - A time plan that turns a list of gaps into ordered steps, owners and dates for meeting a set of requirements.
Computer use · Agents & tools - Letting an AI agent work a computer like a person does - it looks at pictures of the screen and moves the mouse and types.
Conditional access · Identity & 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.
Confidentiality · Fundamentals - Making sure only the right people can see a piece of information.
Confusion matrix · Evaluation & metrics - A small table that counts, for every true class, how often a model gave each answer, showing exactly which mistakes it makes.
Container · Containers & orchestration - A sealed-off box for one program and everything it needs, sharing the host computer's kernel instead of carrying its own.
Container escape · Containers & orchestration - An attack where code running inside a container breaks out of it and gains control of the host machine beneath it.
Container image · Containers & orchestration - The frozen, read-only package of a program and its files from which identical containers are started.
Container orchestration · Containers & orchestration - Letting software run many containers across a group of machines automatically, so nobody has to start and place them by hand.
Container registry · Containers & orchestration - A shared online store where container images are uploaded, given names and versions, and fetched by the machines that run them.
Container runtime · Containers & orchestration - The software on each host that actually starts, stops and walls off containers - containerd is a well-known example.
Context engineering · Prompting & generation - Choosing all a language model gets to see for a task - instructions, fetched documents, tool results, notes - not just the wording.
Context window · Language models - The most text, counted in tokens, that a language model can take in and keep in view at one time, including its own answer.
Contingency plan · Incidents & continuity - A written, approved plan for how the organisation reacts when something goes wrong - who does what, and in which order.
Continuous improvement (PDCA) · Compliance & regulation - A repeating four-step loop - Plan, Do, Check, Act - for getting a little better each round.
Convolutional neural network (CNN) · Model architectures - A neural network built for pictures - it slides small pattern checks across an image to find edges, then shapes, then whole objects.
Cookie · Web & data - A small piece of text a website asks the browser to keep and send back on every visit, so the site can recognise it.
Cosine similarity · Retrieval & search - 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.
Credential · Identity & access - Something a user presents to prove who they are, such as a password, a key card or a fingerprint.
Credential stuffing · Fundamentals - Trying stolen user names and passwords from one leak on many other sites, hoping people used the same password there.
Crisis management · Incidents & continuity - How top management leads the whole organisation through a serious event - decisions, priorities, staff, customers and press.
Critical assets · Risk management - The systems, processes or data the business cannot run without, and so must protect first.
Cross-site request forgery (CSRF) · Application security - 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.
Cross-site scripting (XSS) · Application security - An attack that smuggles a harmful script into a web page, so it runs in the browser of everyone who visits the page.
Cross-validation · Evaluation & metrics - Checking a model fairly by splitting the examples into parts and letting each part in turn be the one held back for testing.
Cryptographic key · Cryptography - The secret value that decides how data is scrambled and restored - whoever holds it can read the protected data.
CSRF token · Application security - 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.
CVE and CVSS · Risk management - A public ID number for each known weakness in software (CVE), plus a 0-10 score for how serious it is (CVSS).
Cyber and information security · Fundamentals - Protecting an organisation's data, systems and ways of working against loss, misuse and interruption.
Cyber Resilience Act (CRA) · Compliance & regulation - The EU law that makes makers of connected products and software build them secure and keep fixing their flaws.

D

D-mærket · Compliance & regulation - A Danish label showing that a company takes care of IT security and data, starting with a free self-check.
Danish NIS2 Act (NIS2-loven) · Compliance & regulation - The Danish law that writes the EU's NIS2 rules into national law and names who checks that firms follow them.
Data breach · Incidents & continuity - An event where private information is seen, taken, changed or lost by people who should not have it.
Data classification · Fundamentals - Sorting data by how sensitive it is - for example public, internal or confidential.
Data controller · Compliance & regulation - The organisation that decides why and how personal data is used, and so carries the main legal duty under GDPR.
Data drift · Evaluation & metrics - 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.
Data ethics · Compliance & regulation - Asking not only whether a use of data is legal, but whether it is fair, open and in line with what people would expect.
Data labeling · Training & optimisation - Having people (or tools) attach the right answer to each example, such as “cat”, “complaint” or “angry”, so a model can learn from it.
Data poisoning · AI risk & governance - Slipping false or harmful examples into the data an AI learns from so that it later behaves the way an attacker wants.
Data processing agreement (DPA) · Compliance & regulation - A written contract that sets how a supplier may handle personal data on your behalf.
Data processor · Compliance & regulation - An outside party that handles personal data on behalf of another organisation and only as that organisation instructs.
Data protection impact assessment (DPIA) · Compliance & regulation - A written check, done before starting, of how a planned use of personal data could harm people and how to reduce that harm.
Database · Web & data - An organised store of data that many programs and users can search, add to and change at the same time without mixing it up.
Decision tree · Machine learning basics - 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.
Decoder · Model architectures - The half of a model that writes output one token at a time, each new token based only on what came before it.
Deep learning · Machine learning basics - Machine learning that uses neural networks with many stacked layers, the approach behind modern image, speech and language tools.
Deepfake · AI risk & governance - A fake but convincing video, image or voice recording made with AI to show someone saying or doing what they never did.
Defence in depth · Fundamentals - Stacking several independent layers of protection so that when one fails, the next one still stops the attacker.
Denial of service (DoS/DDoS) · Fundamentals - An attack that floods a website or service with so much traffic that real users can no longer reach it.
Detection rule · Detection & response - A written condition that a monitoring tool checks against incoming logs, raising an alarm whenever the events match it.
DevSecOps · Software delivery - Building security checks into the everyday work of the teams that write and run software, rather than adding them at the end.
Diffusion model · Model architectures - The kind of generative AI behind many image makers, which starts from random static and cleans it up step by step into a picture.
Digital certificate · Cryptography - 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.
Digital identity · Identity & access - The set of facts that lets a computer system tell one person, device or program apart from all others.
Digital signature · Cryptography - A mark made with a private key that proves who sent a message and that nobody has changed it since.
Dimensionality reduction · Machine learning basics - Squeezing many inputs about each example into a few new ones that keep most of what tells the examples apart.
Disaster recovery plan (DRP) · Incidents & continuity - A technical plan for bringing data and systems back after a breakdown or attack, in a set order and time.
Distributed tracing · Observability - Following one user request as it passes through many services, timing each step, to see where it slowed down or failed.
DNS · Networking - The lookup system that turns names people can read, like example.com, into IP addresses.
Docker · Containers & orchestration - The widely used tool that made containers easy to use - it builds container images, shares them and runs them with a few commands.
DORA · Compliance & regulation - The EU law that makes banks, insurers and other financial firms able to keep running through IT failures and cyber attacks.

E

Embedding · Language models - 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.
Embedding model · Retrieval & search - A model that reads a piece of text and gives back an embedding instead of writing an answer.
Encoder · Model architectures - The half of a model that reads the whole input at once and turns it into embeddings that capture its meaning.
Encryption · Networking - Scrambling data with a secret key so only someone holding the matching key can read it.
End-to-end encryption · Cryptography - Scrambling a message on the sender's device so that only the receiver's device can read it, not even the service carrying it.
Endpoint · Controls & technical basics - Any device that connects to the network at its edge and is used directly - a PC, phone, printer or similar.
Endpoint detection and response (EDR) · Controls & technical basics - Software on each computer and phone that watches for signs of an attack and can stop it on the spot.
Epoch · Training & optimisation - One complete pass of model training through every example in the training data; training often runs for several.
Escalation procedure · Incidents & continuity - Agreed rules for when a problem must be passed up to someone more senior or more expert, and to whom.
Essential and important entities (NIS2) · Compliance & regulation - The two groups of organisations NIS2 covers, sorted by sector and size, with stricter oversight for the essential group.
EU AI Act · AI risk & governance - The EU law that sorts AI systems by how much harm they could cause and sets stricter rules the higher the risk.
EU directive · Compliance & regulation - 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.
EU regulation · Compliance & regulation - A type of EU law that applies directly and identically in every member state, with no national law needed to bring it in.
Excessive agency · AI risk & governance - 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.
Explainability · AI risk & governance - How well people can understand why an AI system reached a particular result.
Exploit · Fundamentals - 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.

F

F1 score · Evaluation & metrics - One number that blends precision and recall, so it stays low unless a model both finds the real cases and avoids wrong flags.
False positive · Detection & response - An alarm about an attack or problem that turns out not to exist, because harmless activity was taken for harmful.
Feature · Machine learning basics - One measurable fact about an example, such as a price or an age, that a model reads as input when it makes a guess.
Feature engineering · Machine learning basics - Turning raw records into useful inputs for a model, by picking, cleaning, combining and reshaping the facts it will read.
Few-shot prompting · Prompting & generation - Showing a language model a handful of worked examples inside the request, so it copies the pattern for the new case.
File system · Operating systems - The way an operating system organises stored data into files and folders and keeps track of who may use each one.
Fill-in-the-middle (FIM) · AI-assisted coding - A training trick that teaches a model to write the missing piece between the text before a gap and the text after it.
Fine-tuning · Language models - Giving an already trained model a short extra round of training on a smaller, focused set of examples to change how it behaves.
Firewall · Networking - A gatekeeper that checks network traffic against rules and lets through only what is allowed.
Foundation model · Model architectures - A large model built once on huge amounts of broad data and then reused as the starting point for many different tasks.

G

Gap analysis · Compliance & regulation - A comparison of what an organisation does today with the requirements it wants to meet.
GDPR · Compliance & regulation - The EU law that protects personal data and gives people rights over how it is used.
General-purpose AI model (GPAI) · AI risk & governance - The EU AI Act's name for a broad model that can handle many different tasks and be built into many other AI products.
Generative AI · Machine learning basics - AI that creates new content (text, images, sound, code) in the style of the examples it learned from, instead of only sorting or scoring.
GitOps · Software delivery - Running systems so that files under version control hold the only true description, and software keeps the live setup matching them.
Governance · Fundamentals - How leadership steers security - setting direction, handing out responsibility and checking that it works.
Governance, risk and compliance (GRC) · Compliance & regulation - The joined-up work of steering security from the top, deciding which dangers to handle, and proving that rules are met.
Gradient boosting · Machine learning basics - A method that adds small decision trees one after another, each built to fix the mistakes the trees before it still make.
Gradient descent · Training & optimisation - The step-by-step method most models learn by, which nudges every setting a little in whichever direction makes the error shrink.
Graphics processing unit (GPU) · AI hardware & serving - 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.
Grey roles · Compliance & regulation - Security jobs that sit between technology, management and people - coordinating and translating rather than hands-on engineering.
Grounding · Retrieval & search - Tying a model's answer to sources supplied with the question, so each claim can be traced back to a given document.
Guardrails · AI risk & governance - Checks placed around an AI system that block unsafe requests going in and harmful or leaking answers coming out.

H

Hallucination · Language models - 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.
Hardening · Controls & technical basics - Making a system harder to attack by turning off what is not needed and changing unsafe default settings.
Hashing · Cryptography - Turning any amount of data into a short, fixed-length value that changes completely if even one character changes.
Health check · Observability - A small automatic test, repeated every few seconds, that asks a running service whether it is alive and able to answer.
HTTP · Web & data - The request-and-answer rules a web browser and a server follow to fetch pages, pictures and data across the internet.
HTTPS · Networking - The way web browsers and websites exchange pages with TLS protecting every message, so no one on the way can read or change them.
Human error · Fundamentals - An honest mistake by a person - a wrong click, a lost laptop, a file sent to the wrong address - that harms security.
Human factor · Fundamentals - How people's habits, stress, trust and attention shape security - a common way in for attackers, but also a line of defence.
Human firewall · People, culture & awareness - A workforce that acts as the first line of defence by spotting and stopping attacks aimed at people.
Human-in-the-loop (HITL) · Agents & tools - Designing an AI system so a person must check or approve its work at key points before it takes effect.
Hybrid search · Retrieval & search - Running a word-matching search and a meaning-based search side by side and merging their results into one list.
Hyperparameter · Training & optimisation - 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.
Hypervisor · Cloud - The layer of software that splits one physical computer into several virtual machines and keeps them apart.

I

Identity federation · Identity & access - An agreement between organisations to trust each other's logins, so a person proven at home is let in elsewhere.
Identity provider · Identity & access - A trusted service that stores users' identities, checks their logins and vouches for them to other applications.
Impact · Fundamentals - How much harm an event would do to the business if it actually happened - in money, time, trust or safety.
Incident reporting · Incidents & continuity - Telling the right people and authorities about a serious security event, quickly and within set deadlines.
Incident response · Incidents & continuity - The organised way a company spots, stops and cleans up after a security attack or accident, then gets back to normal.
Indicator of compromise (IoC) · Detection & response - 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.
Inference · Machine learning basics - Using an already trained model to produce an answer for new input, which is what happens each time you ask a chat assistant something.
Information security coordinator · Compliance & regulation - The person who keeps an organisation's day-to-day security work organised, tracked and reported to management.
Information security management system (ISMS) · Compliance & regulation - The set of policies, roles, processes and records an organisation uses to run its information security in a planned, repeatable way.
Infrastructure as a service (IaaS) · Cloud - The cloud model where you rent bare building blocks - machines, storage and network - and run everything on top yourself.
Infrastructure as code (IaC) · Software delivery - Describing servers, networks and cloud settings in text files that a tool reads to build them, instead of setting them up by hand.
Input validation · Application security - Checking every piece of data a program receives against strict rules before using it, and turning away anything that does not fit.
Insider threat · Fundamentals - Harm that comes from someone already trusted inside the organisation, whether they mean to do damage or simply make a mistake.
Instruction tuning · Training & optimisation - Extra training on many written requests paired with good answers, which turns a text-continuing base model into one that follows orders.
Integrity · Fundamentals - Making sure information stays correct and complete, and is not changed by accident or without permission.
Internet · Networking - The worldwide network of networks that lets almost any connected device reach almost any other.
Intrusion detection system (IDS) · Controls & technical basics - A watcher that inspects network traffic or a machine's activity and warns when it spots signs of an attack - without stopping it.
Intrusion prevention system (IPS) · Controls & technical basics - A guard placed in the path of network traffic that recognises signs of an attack and blocks them as they happen.
IP address · Networking - A number that identifies a device on a network so that data can be delivered to it.
ISO 27000 series · Compliance & regulation - The family of international standards for information security, with ISO 27001 at its centre and guides built around it.
ISO 27001 · Compliance & regulation - The international standard for running an information security management system that can be certified.
ISO 27001 Annex A · Compliance & regulation - 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.
ISO 27002 · Compliance & regulation - A guidance standard describing each security control in detail - what it is for and how to put it in place.
IT operations · Fundamentals - The team and daily work that keep an organisation's computers, systems and networks running.

J

Jailbreak · AI risk & governance - Talking an AI chat assistant out of its own safety rules with cleverly worded requests, such as role-play or made-up emergencies.
JSON · Web & data - A simple text format for writing down data as named values and lists, easy for both people and programs to read.

K

k-means clustering · Machine learning basics - 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.
Kernel · Operating systems - The core of the operating system, which has full control of the machine and decides what every program may do.
Key management · Cryptography - Looking after cryptographic keys over their whole life - making, storing, handing out, changing and finally destroying them.
Keyword search · Retrieval & search - Finding texts that contain the same words as the question, ranked by how often those words appear and how rare they are overall.
Knowledge cutoff · Language models - The date after which a language model saw no new text, so on its own it knows nothing about events that came later.
Knowledge distillation · AI hardware & serving - 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.
Kubernetes · Containers & orchestration - The most widely used open-source system for container orchestration, first built at Google and released in 2014.
KV cache · AI hardware & serving - Memory where a language model keeps work it already did on earlier tokens, so each new word does not mean rereading everything.

L

Label · Machine learning basics - The right answer attached to a training example, such as "spam" or a sale price, that a model learns to give on its own.
Large language model (LLM) · Language models - 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.
Latency · AI hardware & serving - 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.
Lateral movement · Fundamentals - What an attacker does after getting a first foothold - spreading from machine to machine inside the network.
Learning rate · Training & optimisation - The setting that decides how big a step a model takes each time it adjusts itself to make fewer mistakes during learning.
Legacy system · Fundamentals - An old system the business still depends on but that can no longer be updated, replaced or protected in the normal way.
Lessons learned · Incidents & continuity - Looking back after an incident or exercise to see what worked, what failed and what to change next time.
Likelihood · Fundamentals - How probable it is that a given threat will actually use a weakness and cause harm within a certain period.
Linear regression · Machine learning basics - A simple model that predicts a number by adding up each input times its own weight, choosing the weights that fit past examples best.
LLM-as-a-judge · Evaluation & metrics - Using one large language model to grade the answers of another against a written scoring guide, instead of paying people to read them all.
Log · Operating systems - A time-stamped record of events that a system or program writes down as they happen.
Log management · Detection & response - Collecting logs from every system into one place, in one format, kept safe from change and for as long as they are needed.
Log retention · Detection & response - Deciding how long each kind of log is kept before it is deleted - long enough to look into incidents, but no longer than needed.
Logistic regression · Machine learning basics - A simple model that sorts cases into two groups by turning a weighted sum of the inputs into a chance between 0 and 1.
Loss function · Training & optimisation - The scoring rule that turns how wrong a model's answer is into a single number, which model training then tries to push down.
Low-rank adaptation (LoRA) · Training & optimisation - A cheap way to fine-tune a big model - freeze the original weights and train only a small add-on that nudges its behaviour.

M

Machine learning · Machine learning basics - Building computer systems that find patterns in examples and use them to make guesses, instead of following rules a person wrote.
Malware · Fundamentals - Harmful software that sneaks onto a computer or phone to steal, spy, damage or take control.
Man-in-the-middle attack · Fundamentals - An attacker secretly placed between two parties who reads or changes their messages while each believes they talk directly.
Management responsibility · Compliance & regulation - The duty of top leaders to own, approve and be able to show the organisation's security work.
MCP server · Agents & tools - A small program that offers tools or data to AI apps through the Model Context Protocol, such as reading mail or searching files.
Metrics · Observability - Numbers a system records at regular times, such as requests per second or memory used, so trends can be charted and compared.
Microservices · Containers & orchestration - A way of building an application as many small, separate services that each do one job and talk to each other over an API.
MITRE ATT&CK · Detection & response - A free, public catalogue of the goals and methods real attackers use, giving defenders a shared language for how attacks unfold.
Mixture of experts (MoE) · Model architectures - 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.
Model card · AI risk & governance - 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.
Model Context Protocol (MCP) · Agents & tools - An open standard for plugging tools and data into AI assistants, so each tool is hooked up once and works in many apps.
Model evaluation (evals) · Evaluation & metrics - The practice of checking how well an AI system does its job, with scores, public tests, human review and deliberate attacks.
Model parameter · Training & optimisation - One of the numbers inside a model that is set by learning from data; their count is how model size is usually stated.
Model serving · AI hardware & serving - Keeping a trained model running on machines so other programs can send it questions over an API and get answers back.
Model training · Machine learning basics - The costly, one-off stage where a model looks at training data again and again and tunes its internal numbers until its guesses improve.
Model weights · Training & optimisation - The learned numbers that set how strongly each part of a neural network influences the next; in practice, the file that is the model.
Monitoring · Observability - Watching a set of chosen measurements on systems over time and warning people when one moves outside its normal range.
Multi-agent system · Agents & tools - A setup where several AI agents share a job - often a lead agent splits the work and hands parts to helper agents.
Multi-factor authentication · Controls & technical basics - 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.
Multimodal model · Model architectures - A model that can take in, and sometimes produce, more than one kind of content - such as text, photos and speech - in one conversation.

N

Nearest-neighbour search · Retrieval & search - Finding the few stored items that sit closest to a given one, usually trading a little exactness for a lot of speed.
Network · Networking - A set of connected devices that can send data to each other over cables or radio signals.
Network segmentation · Networking - Splitting one network into separate zones, so a problem in one zone cannot easily spread to the others.
Neural network · Machine learning basics - A model made of many small linked units that each weigh their inputs and pass a number on, loosely inspired by the brain.
Next-token prediction · Language models - How a language model writes - it guesses the single most fitting next piece of text, adds it, and repeats until the answer is done.
NIS1 Directive · Compliance & regulation - The first EU-wide cybersecurity law, from 2016, which set security and reporting duties for key service providers until NIS2 replaced it.
NIS2 Directive · Compliance & regulation - The EU cybersecurity law that sets shared security duties for organisations in important and critical sectors.
NIS2 minimum requirements · Compliance & regulation - The baseline list of security measures every organisation under NIS2 must have in place.
NIST Cybersecurity Framework (CSF) · Compliance & regulation - A free US framework that sorts security work into six broad goals, from steering it to recovering after an attack.
Non-repudiation · Fundamentals - Proof of who did something that is strong enough that they cannot later deny having done it.
Nudging · People, culture & awareness - Small, gentle prompts that make the safe choice the easy one, without forbidding anything.

O

OAuth · Identity & access - A way to let one app act on your behalf in another service, with a limited pass instead of your password.
Observability · Observability - How well you can work out what is going on inside a running system just from the signals it sends out.
One-time password (OTP) · Controls & technical basics - A short code that works for a single login and then expires, sent by text message or shown in an app.
Open-weight model · Model architectures - A model whose learned numbers are published for anyone to download and run themselves, instead of only being reachable through an API.
OpenID Connect (OIDC) · Identity & access - A login standard built on top of OAuth that tells an app who the user is, not just what it may do.
Operating system · Operating systems - The base software that runs a computer, shares it between programs and keeps them from interfering with each other.
Organisational control · Controls & technical basics - A safeguard made of rules, roles and routines - who decides, who does what, and how work must be done.
Overfitting · Machine learning basics - When a model learns its training examples by heart, including their noise, and then does badly on new cases it has not seen.
OWASP Top 10 · Application security - A widely used, regularly updated list of the ten most serious kinds of security flaw found in web applications.

P

Packet · Networking - A small, labelled chunk of data that travels across a network on its own and is put back together at the end.
Passkey · Identity & access - A login without a password, where your device proves who you are with a secret key that never leaves it.
Password · Identity & access - A secret string of characters, known only to the user, typed in to prove they are who they claim to be.
Patch · Operating systems - A small piece of software from a vendor that fixes a flaw - often a vulnerability - in a program already installed.
Patch management · Controls & technical basics - The routine of keeping all software up to date so that known weaknesses are closed before attackers use them.
Penetration test · Controls & technical basics - An agreed, simulated attack in which skilled testers try to break in, to show how well systems really hold up.
People control · Controls & technical basics - A safeguard aimed at staff themselves - screening, training, clear duties and what happens when someone joins or leaves.
Perimeter security · Fundamentals - Guarding the edge between an organisation's own network and the outside world, and trusting what is already inside.
Permission · Operating systems - A specific right given to an account, such as to read, change or delete a file, or to run a program.
Personal data · Compliance & regulation - Any information about a living person who can be named or traced, directly or by putting pieces together.
Phishing · People, culture & awareness - Fake emails or messages sent in bulk to trick people into handing over information or clicking something harmful.
Phishing simulation · People, culture & awareness - Sending staff harmless fake phishing mails to see who clicks and to teach them to spot the real thing.
Physical security · Fundamentals - Protecting buildings, rooms and equipment so that nobody can simply walk in, take, break or plug into them.
Pipeline · Software delivery - A fixed, automatic chain of steps that takes a code change from saved file to running software, stopping if any step fails.
Platform as a service (PaaS) · Cloud - The cloud model where the provider runs the machines and operating system, and you only bring your own program and its data.
Pod · Containers & orchestration - The smallest unit Kubernetes runs - one or a few tightly linked containers that share a network address and storage.
Port · Networking - A number that picks out which program on a device should receive incoming network data.
Precision · Evaluation & metrics - Of all the cases a model flags as positive, the share that really are; in security terms, how many alerts were real.
Pretexting · People, culture & awareness - Inventing a believable cover story and role, such as a new colleague or an auditor, to get someone to share information.
Pretraining · Training & optimisation - The first, huge and costly stage of teaching a model, reading vast amounts of text to pick up general patterns before any special task.
Principle of least privilege · Identity & access - Giving every user, program and service only the permissions its task needs, and nothing more.
Privacy by design · Compliance & regulation - The GDPR principle that protection of personal data must be built into systems from the start.
Privilege escalation · Fundamentals - An attacker who has a small foothold gaining more rights than they were given, up to full control of the system.
Privileged access management (PAM) · Identity & access - Tools and rules that lock away admin rights, hand them out only when needed and record what is done with them.
Privileged account · Identity & access - An account with power beyond normal use, such as installing software, changing settings or managing other users.
Process · Operating systems - A program while it is running, with its own space in memory and the rights of the account that started it.
Prompt · Language models - The text you give a language model - a question, an order, pasted files - that it treats as its starting point for an answer.
Prompt caching · AI hardware & serving - 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.
Prompt engineering · Prompting & generation - The craft of wording, ordering and testing the text you send a language model so that it gives useful answers more often.
Prompt injection · AI risk & governance - Hiding instructions in the text an AI system reads so that it ignores its own rules and follows the attacker instead.
Protocol · Networking - An agreed set of rules for how devices on a network format, send and answer messages.
Public key infrastructure (PKI) · Cryptography - The system of trusted issuers, rules and records that hands out digital certificates and says which ones to believe.
Public-key cryptography · 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.

Q

Qualitative risk analysis · Risk management - Rating risks with words or simple scales, such as low, medium and high, based on judgement rather than exact figures.
Quantitative risk analysis · Risk management - Putting numbers on risks - how often a loss may happen and how much it would cost - to compare them in money.
Quantization · AI hardware & serving - Storing a model's numbers with fewer digits so it takes less memory and runs faster, at the cost of a little quality.

R

Random forest · Machine learning basics - A model that builds many slightly different decision trees on random parts of the data and lets them vote on the answer.
Ransomware · People, culture & awareness - Harmful software that locks an organisation's data and demands payment to unlock it.
Reasoning model · Language models - 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.
Recall · Evaluation & metrics - Of all the real positive cases, the share a model manages to find; in security terms, how many real attacks were caught.
Recovery objectives (RTO/RPO) · Incidents & continuity - Two agreed limits for a failure - how long a system may be down (RTO) and how much recent data may be lost (RPO).
Regression · Machine learning basics - 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.
Regularization · Training & optimisation - Any rule added during learning that holds a model back from fitting its examples too closely, so it does better on new cases.
Reinforcement learning · Machine learning basics - Machine learning by trial and error, where a system acts, gets a reward or a penalty, and slowly learns which actions pay off.
Reinforcement learning from human feedback (RLHF) · Training & optimisation - Improving a model by having people rank its answers, teaching a scorer from those rankings, then training the model to earn high scores.
Reranking · Retrieval & search - A second, more careful pass that reorders a first rough list of search results so the most useful ones end up on top.
Residual risk · Risk management - The risk still left after controls are in place, because no protection removes danger completely.
REST API · Web & data - 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.
Retrieval-augmented generation (RAG) · Language models - Letting a language model first look up relevant passages in your own documents and then answer from them, instead of from memory alone.
Risk · Fundamentals - How likely it is that a threat uses a vulnerability, combined with how bad the damage would be.
Risk acceptance · Risk management - A deliberate, recorded decision to live with a risk instead of spending more to reduce it.
Risk appetite · Risk management - How much risk leadership is willing to live with to reach the company's goals.
Risk assessment · Risk management - Working out what could go wrong, how likely it is and how much harm it would do, so the biggest risks get handled first.
Risk avoidance · Risk management - Removing a risk entirely by not doing, or no longer doing, the activity that creates it.
Risk heat map · Risk management - A colour-coded grid that places each risk by how likely and how harmful it is, so the worst stand out in red.
Risk identification · Risk management - The first step of a risk assessment - finding and writing down what could go wrong, to what, and why.
Risk management · Risk management - The ongoing work of finding, weighing and handling risks so that time and money go where they protect the most.
Risk mitigation · Risk management - Lowering a risk by adding controls that make it less likely to happen or less harmful if it does.
Risk monitoring · Risk management - Keeping an eye on known risks over time, so changes are caught and decisions are revisited before they go stale.
Risk profile · Risk management - The overall picture of which dangers an organisation faces and how serious they are, given its size, sector, data and systems.
Risk transfer · Risk management - Moving the financial cost of a risk to another party, usually through insurance or a contract with a supplier.
Risk treatment · Risk management - Choosing what to do about each risk - accept it, reduce it, share it with someone else, or avoid it altogether.
Role-based access control (RBAC) · Identity & access - Giving permissions to job roles rather than to individual people, and then giving people the roles that fit their job.
Router · Networking - A device that joins networks together and passes each packet on toward its destination.
Runbook · Observability - Written step-by-step instructions for handling one known situation, such as a certain alarm, so anyone on call can act fast.

S

Same-origin policy · Web & data - A browser rule that stops a page from one site reading data that belongs to another site open in the same browser.
SAML · Identity & access - An older, widely used standard for passing a signed “this user has logged in” message from an identity provider to an app.
Sampling · Prompting & generation - 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.
Secrets management · Cloud - Keeping passwords, keys and tokens that programs use in one guarded store, instead of scattered in code and files.
Secure boot · Operating systems - A start-up check that lets a computer run only boot software and a kernel carrying a trusted digital signature.
Secure development lifecycle (SDL) · Application security - A fixed set of security steps built into every stage of making software, from planning and design through testing to release.
Security awareness · People, culture & awareness - What staff know about security and how they act on it in daily work.
Security by design · Fundamentals - Thinking security into systems and processes from the very start, instead of adding it at the end.
Security control · Fundamentals - A measure that lowers risk - technical, like a lock on a system, or organisational, like a rule or training.
Security culture · People, culture & awareness - The shared habits and attitudes toward security that shape how people act when nobody is checking.
Security framework · Compliance & regulation - A ready-made, shared structure of goals and controls that an organisation follows to build and check its security work.
Security incident · Fundamentals - An event that has harmed, or may soon harm, the confidentiality, integrity or availability of information or systems.
Security maturity · Compliance & regulation - How far an organisation's security has grown - from random and tied to single people to planned, measured and steadily improving.
Security metrics (KPIs) · Compliance & regulation - Numbers chosen in advance to show whether security work is having the effect it should.
Security monitoring · Controls & technical basics - Keeping a steady watch on systems and networks so that signs of attack or misuse are spotted while there is still time to act.
Security operations centre (SOC) · Controls & technical basics - A team that watches an organisation's systems around the clock and acts when an alarm points to a real attack.
Security policy · Fundamentals - A document that sets out an organisation's goals, responsibilities and principles for information security.
Self-assessment · Compliance & regulation - An organisation checking its own security against a set list of questions or criteria, without an outside inspector.
Self-supervised learning · Machine learning basics - Machine learning where the right answers come from the data itself, for instance hiding a word in a sentence and guessing it back.
Semantic search · Retrieval & search - Finding text by what it means rather than by the exact words it uses, so a question can match a passage phrased differently.
Sensitive information disclosure · AI risk & governance - An AI system revealing private or secret details, such as personal data or business secrets, to someone who should not see them.
Server · Networking - A computer or program that waits for requests over a network and answers them, such as sending a web page or storing email.
Service · Operating systems - A program that runs in the background without a user, often starting with the computer and waiting to handle requests.
Service account · Identity & access - An account used by a program rather than a person, so that software can log in to other systems on its own.
Service level agreement (SLA) · Observability - 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.
Service level objective (SLO) · Observability - An internal target for how well a service should work, such as 99.9% of requests answered within a second over 30 days.
Session · Identity & access - The period in which a system remembers that a user has logged in, so they need not prove who they are at every step.
Session hijacking · Fundamentals - Taking over someone's session after they have logged in, so the attacker is treated as that user without knowing the password.
Shadow AI · AI risk & governance - Staff using AI tools at work without the organisation knowing about them or having approved them.
Shadow IT · People, culture & awareness - Apps and tools staff use for work without the IT department knowing about or approving them.
Shared responsibility model · Cloud - The split of security duties between a cloud provider and its customer, which shifts with the kind of service bought.
SIEM · Controls & technical basics - A system that gathers logs from across the organisation in one place and raises an alarm when something looks wrong.
Single sign-on (SSO) · Identity & access - Logging in once to reach many separate applications, with a trusted identity provider vouching for the user to each.
Slopsquatting · AI-assisted coding - An attack where criminals publish harmful packages under the made-up names that AI tools keep inventing for code.
Small language model (SLM) · Model architectures - A language model small enough to run cheaply on a laptop or phone, trading some broad skill for speed, privacy and low cost.
Smishing · People, culture & awareness - Phishing sent as a text message, usually a short, urgent note with a link or a number to call.
SOAR · Detection & response - A platform that ties a security team's tools together and runs the routine steps of handling an alarm by itself.
Social engineering · People, culture & awareness - Manipulating people into giving away information or access, instead of breaking into systems directly.
Software as a service (SaaS) · Cloud - The cloud model where you simply use a finished program over the internet, and the provider runs everything behind it.
Software bill of materials (SBOM) · Software delivery - A list of every component and outside library a piece of software contains, so its owners know exactly what is inside it.
Software composition analysis (SCA) · Software delivery - Automatic checking of the outside libraries a program is built from, looking for known flaws and licence problems.
Software supply chain · Software delivery - Everything and everyone that goes into making software you run, from outside code parts to the tools that build and ship it.
Spear phishing · People, culture & awareness - A phishing message tailored to one person or team, made to look like it comes from someone they know.
Spec-driven development · AI-assisted coding - Writing down exactly what the software must do, agreed by people, before letting AI tools write the code from that plan.
SQL injection · Application security - An attack where text typed into a form is read by the database as a command, letting an outsider read or change its data.
Statement of Applicability (SoA) · Compliance & regulation - A document listing every control in the ISO 27001 annex, saying whether each is used, and giving the reason.
STRIDE · Application security - A memory aid that sorts threats into six kinds, so a team checks every part of a design for each kind in turn.
Structured output · Prompting & generation - Making a language model answer in a fixed, machine-readable shape - set fields in JSON - so other software can use the reply directly.
Supervised learning · Machine learning basics - Machine learning from examples that come with the right answer attached, such as emails already marked spam or not spam.
Supervisory authority · Compliance & regulation - The public body in each EU country that oversees GDPR, handles complaints and can seek fines; in Denmark, Datatilsynet.
Supplier management · Compliance & regulation - Making sure outside partners who handle your data or systems meet your security demands.
Supply chain attack · Fundamentals - Breaking into many targets at once by first taking over a supplier, product or update they all trust.
Symmetric encryption · Cryptography - Encryption where the same secret key both locks and unlocks the data, so sender and receiver must share it in advance.
Synthetic data · Training & optimisation - Made-up examples produced by a program or another AI model to look like real records, used where real examples are scarce or private.
System prompt · Prompting & generation - 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.

T

Table-top exercise · Incidents & continuity - A practice session around a table where a team talks through a made-up crisis step by step to test its plans.
TCP/IP · Networking - The family of protocols that the internet and most other networks use to address, send and deliver data.
Technical control · Controls & technical basics - A safeguard built into hardware or software, which works automatically once it is set up.
Telemetry · Observability - The data a running system sends out about itself, mainly logs, metrics and traces, so people can see how it is doing.
Temperature · Prompting & generation - A per-request dial - low keeps a language model's wording steady and repeatable, high makes it more varied and less predictable.
Tensor processing unit (TPU) · AI hardware & serving - Google's own chip made only for the number work inside neural networks, mostly rented out through Google Cloud rather than sold.
Test set · Evaluation & metrics - Examples locked away while a model is built and opened once at the end to give an honest final score.
Threat · Fundamentals - Anything that could harm the organisation - an attacker, a careless mistake, a fire or a power cut.
Threat actor · Fundamentals - The person or group behind an attack, such as a criminal gang, a foreign state, an activist or a careless insider.
Threat hunting · Detection & response - Searching on purpose for attackers who may already be inside the network, without waiting for an alarm to go off.
Threat intelligence · Risk management - Up-to-date knowledge about current attackers and their methods, gathered so attacks can be stopped before they land.
Threat landscape · Risk management - A picture of the kinds of threats a company could face right now, and who or what is behind them.
Threat modelling · Application security - 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.
Throughput · AI hardware & serving - How much work a system gets through per second in total - for AI services, often counted as tokens or requests handled each second.
Time to first token (TTFT) · AI hardware & serving - How long a user waits after sending a prompt before the first piece of the answer appears on screen.
TLS · Networking - The protocol that wraps data sent over TCP/IP in an encrypted channel after checking the other side's certificate.
Token · Language models - 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.
Tokenizer · Language models - 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.
Tool calling · Agents & tools - How a language model asks outside code to do something for it - look something up, run a task - and then reads back the result.
Top-p sampling · Prompting & generation - 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%.
Training data · Machine learning basics - The examples a model learns from; its behaviour, its blind spots and its mistakes all come from what is in them.
Transfer learning · Machine learning basics - Reusing what a model already learned on one big task as the starting point for a new, related task, instead of starting from zero.
Transformer · Language models - The neural network design behind today's language models, which weighs how every word in a text relates to every other word.
Two-factor authentication · Controls & technical basics - The most common form of MFA, where logging in needs exactly two separate proofs, usually a password and a one-time code.

U

Underfitting · Training & optimisation - 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.
Unsupervised learning · Machine learning basics - Machine learning from examples with no answers attached, where the model finds groups, patterns or odd cases on its own.
URL · Web & data - A written address that says where something lives on the internet and how to reach it, such as a web page or a file.
User account · Identity & access - A record in a system that lets a particular person or program log in, and holds the permissions it has been given.

V

Validation set · Evaluation & metrics - Examples held back from training and checked again and again while building a model, to choose its settings and decide when to stop.
Vector database · Retrieval & search - A store built to keep huge numbers of embeddings and quickly return the ones closest in meaning to a question.
Version control · Software delivery - 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.
Vibe coding · AI-assisted coding - Building software by describing what you want to an AI and accepting the code it writes without reading it.
Virtual machine · Cloud - A whole computer made in software, with its own operating system, running side by side with others on one physical machine.
Vishing · People, culture & awareness - Tricking people over the phone or a voice call into giving away information, codes or money.
VPN · Networking - An encrypted tunnel across a public network that makes a distant device act as if it were inside a private one.
Vulnerability · Fundamentals - A weakness that a threat can use to cause harm.
Vulnerability assessment · Controls & technical basics - A review of systems to find their weaknesses and rank which ones matter most to fix first.
Vulnerability scanning · Controls & technical basics - An automatic, repeated check of systems against a list of known weaknesses, producing a report of what was found.

W

Web application · Web & data - A program you use through a web browser, with its logic and data kept on a server instead of installed on your own machine.
Web application firewall (WAF) · Application security - A filter in front of a website that reads each web request and blocks those that look like known attacks.
Web browser · Web & data - The program people use to visit websites - it fetches pages from servers and turns them into something you can read and click.

Z

Zero Trust · Controls & technical basics - A security principle of never trusting anyone automatically - every request is checked, even from inside the network.
Zero-day vulnerability · Fundamentals - A flaw that attackers know about before the maker does, so on the day it is used there is no fix to install.
Zero-shot prompting · Prompting & generation - Asking a language model to do a task from an instruction alone, with no worked examples to copy.