Cloud computing

Computing resources supplied over a network when needed, including processing, storage and software. The cloud still runs on physical equipment; a service can depend on several providers and facilities.

Cloud computing lets a customer obtain computing resources over a network without arranging every underlying machine separately. NIST’s definition describes shared resources that can be provided and released quickly as demand changes. Those resources can include servers, storage, networks and applications.

The term describes how computing is supplied. It does not mean that data has stopped occupying physical equipment, or that every cloud service uses the same buildings. Providers, locations and arrangements differ.

This matters when considering disruption. A customer may depend on its cloud provider and on other services needed to reach or use it. In 2026 the Bank of England’s CORST exercise is exploring a cloud-provider and third-party disruption scenario. That is a test of dependencies and recovery, not a declaration that all cloud systems will fail together.