{"licence":{"name":"CC BY-SA 4.0","spdx":"CC-BY-SA-4.0","url":"https://creativecommons.org/licenses/by-sa/4.0/","attribution":"Atlas, a bilingual technical dictionary (https://cmaintz.github.io/tech-atlas/)"},"id":"platform/cloud-computing","url":{"en":"https://cmaintz.github.io/tech-atlas/en/terms/platform/cloud-computing/","da":"https://cmaintz.github.io/tech-atlas/da/terms/platform/cloud-computing/"},"term":{"en":"Cloud computing","da":"Cloud computing"},"aka":{"en":["the cloud"],"da":["skyen"]},"domain":["platform"],"cluster":"cloud","layer":"infrastructure","status":"current","era":2006,"summary":{"en":"Renting computing power, storage and software over the internet from a provider, paying for what you use instead of owning it.","da":"At leje regnekraft, lager og software over internettet fra en udbyder og betale for forbruget i stedet for at eje det."},"body":{"formal":{"en":"A model for on-demand network access to a shared pool of computing resources that can be taken into use and released quickly with minimal effort or contact with the provider; NIST defines it by five essential characteristics and three service models.","da":"En model for netværksadgang efter behov til en fælles pulje af IT-ressourcer, der hurtigt kan tages i brug og frigives med minimal indsats og kontakt med udbyderen; NIST definerer den ud fra fem kendetegn og tre servicemodeller."},"plain":{"en":"Like getting electricity from the grid instead of running your own generator - you plug in, use what you need and pay the bill.","da":"Som at få strøm fra elnettet i stedet for at have sin egen generator - man sætter stikket i, bruger det, man har brug for, og betaler regningen."},"inPractice":{"en":"A Danish municipality moves its case-handling system from its own server room into a provider's data centre; staff reach it over the internet, and the IT manager now looks after a contract instead of hardware.","da":"En dansk kommune flytter sit sagsbehandlingssystem fra eget serverrum til en udbyders datacenter; medarbejderne får adgang til det via internettet, og IT-chefen passer nu en kontrakt i stedet for hardware."},"whyItMatters":{"en":"The organisation's data now sits on machines it neither owns nor sees, so its security depends as much on contracts, settings and trust in the provider as on its own staff.","da":"Organisationens data ligger nu på maskiner, den hverken ejer eller ser, så sikkerheden afhænger lige så meget af kontrakter, indstillinger og tillid til udbyderen som af egne medarbejdere."}},"deepDive":{"en":"The reference definition is still NIST SP 800-145 (Mell and Grance, September 2011): five essential characteristics (on-demand self-service, broad network access, resource pooling, rapid elasticity, measured service), three service models (IaaS, PaaS, SaaS) and four deployment models (public, private, community, hybrid). ISO/IEC 17788:2014 gives a comparable vocabulary. The definition is deliberately technology-neutral and works as a test: a server rented by the month and set up through support tickets fails self-service and elasticity, so it is hosting or outsourcing rather than cloud in the NIST sense. Later labels such as serverless/FaaS, containers-as-a-service and DBaaS refine the three service models rather than replace them.\n\nResource pooling rests on virtualisation (hypervisors with hardware-assisted nested paging, software-defined overlay networks such as VXLAN) and on a control plane exposed as an authenticated API. Every console click is an API call signed with credentials (for example AWS Signature Version 4), authorised by the provider's IAM and recorded in an audit trail such as AWS CloudTrail, Azure Activity Log or Google Cloud Audit Logs. The split between control plane and data plane is the central security property: whoever holds control-plane credentials can snapshot disks, open network rules or delete backups without ever touching the workload itself. Elasticity is implemented by autoscaling against metrics, and measured service by per-second or per-request metering.\n\nThe failure modes differ from on-premises operation. Availability zones are isolated failure domains inside a region, so surviving the loss of a whole region requires an explicit multi-region design. Multi-tenancy adds cross-tenant side-channel risk (the Spectre/Meltdown class disclosed in 2018), and elasticity adds cost runaway, typically cryptomining on stolen credentials. Egress fees and proprietary managed services create lock-in; the EU Data Act (Regulation (EU) 2023/2854), applicable since 12 September 2025, imposes switching obligations on providers of data processing services and phases out switching charges entirely from 12 January 2027.\n\nLegally, a provider processing personal data on the customer's instructions is a processor under GDPR Art. 28, which requires a data processing agreement; transfers to third countries fall under Chapter V, shaped by the Schrems II judgment (C-311/18, July 2020) and the EU-US Data Privacy Framework adequacy decision of July 2023. Cloud computing service providers are themselves listed under digital infrastructure in NIS2 Annex I. Cloud computing should be kept distinct from virtualisation, which is an enabling technology, and from the shared responsibility model, which describes how operating duties are split once the service is bought.","da":"Referencedefinitionen er stadig NIST SP 800-145 (Mell og Grance, september 2011): fem kendetegn (selvbetjening efter behov, bred netværksadgang, ressourcepuljer, hurtig elasticitet og målt forbrug), tre servicemodeller (IaaS, PaaS, SaaS) og fire udrulningsmodeller (offentlig, privat, fællesskabs- og hybrid sky). ISO/IEC 17788:2014 giver et tilsvarende begrebsapparat. Definitionen er bevidst teknologineutral og kan bruges som test: en server, der lejes pr. måned og sættes op via supportsager, opfylder hverken selvbetjening eller elasticitet og er derfor hosting eller outsourcing, ikke cloud i NIST's forstand. Nyere betegnelser som serverless/FaaS, containers-as-a-service og DBaaS er forfinelser af de tre servicemodeller, ikke erstatninger for dem.\n\nRessourcepuljerne bygger på virtualisering (hypervisorer med hardwareunderstøttet nested paging og softwaredefinerede overlay-netværk som VXLAN) og på et kontrolplan, der udstilles som et autentificeret API. Hvert klik i konsollen er et API-kald signeret med loginoplysninger (fx AWS Signature Version 4), som udbyderens IAM autoriserer, og som logges i et revisionsspor som AWS CloudTrail, Azure Activity Log eller Google Cloud Audit Logs. Adskillelsen mellem kontrolplan og dataplan er den centrale sikkerhedsegenskab: den, der har adgang til kontrolplanet, kan tage snapshots af diske, åbne netværksregler eller slette backup uden nogensinde at røre selve arbejdsbelastningen. Elasticitet realiseres med autoskalering ud fra metrikker, og målt forbrug med afregning pr. sekund eller pr. kald.\n\nFejlscenarierne er anderledes end ved egen drift. Availability zones er isolerede fejldomæner inden for en region, så man kun overlever tabet af en hel region med et bevidst design på tværs af regioner. Multi-tenancy giver risiko for sidekanaler mellem kunder (Spectre/Meltdown-klassen fra 2018), og elasticitet giver risiko for løbske omkostninger, typisk cryptomining på stjålne nøgler. Egress-gebyrer og proprietære managed services skaber lock-in; EU's dataforordning (forordning (EU) 2023/2854), der har fundet anvendelse siden 12. september 2025, pålægger udbydere af databehandlingstjenester forpligtelser om skift af udbyder og afskaffer gebyrer for skift helt fra 12. januar 2027.\n\nJuridisk er en udbyder, der behandler personoplysninger efter kundens instruks, databehandler efter databeskyttelsesforordningens art. 28, hvilket kræver en databehandleraftale; overførsler til tredjelande falder under kapitel V, præget af Schrems II-dommen (C-311/18, juli 2020) og Kommissionens tilstrækkelighedsafgørelse om EU-US Data Privacy Framework fra juli 2023. Udbydere af cloud computing-tjenester er selv opført under digital infrastruktur i NIS2-direktivets bilag I. Cloud computing bør holdes adskilt fra virtualisering, som er en understøttende teknologi, og fra modellen for delt ansvar, som beskriver, hvordan driftsopgaverne fordeles, når tjenesten er købt."},"edges":[{"type":"requires","to":"cs/internet","confidence":"high","strength":"normal"},{"type":"requires","to":"cs/server","confidence":"high","strength":"normal"},{"type":"used-with","to":"security/data-processing-agreement","confidence":"high","strength":"normal"},{"type":"used-with","to":"ai/inference","confidence":"high","strength":"normal"},{"type":"used-with","to":"ai/gpu","why":{"en":"Most teams rent GPUs by the hour from cloud providers instead of buying them.","da":"De fleste teams lejer GPU'er per time hos cloududbydere i stedet for at købe dem."},"confidence":"medium","strength":"normal"}],"depth":5,"sources":[{"title":"NIST SP 800-145 - The NIST Definition of Cloud Computing","tier":"standard","publisher":"NIST"}],"draft":true}