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Broad network access means cloud capabilities are reachable over a network through standard mechanisms usable by different kinds of client platforms. NIST lists phones, tablets, laptops and workstations as examples.^[ref]

For example, a browser interface and an application programming interface can expose the same service to interactive users and automated analyses. Network accessibility does not imply public authorization: a private cloud can restrict authenticated clients while still using broadly supported network interfaces. Latency, bandwidth and intermittent connectivity affect how an application should divide work between client and service; an accessible remote operation is not equivalent to a local memory access.

Cloud computing supplies configurable computation resources through a computer network, drawing on a shared pool that users can obtain and release with little provider intervention. The NIST definition distinguishes five characteristics: on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service. Together these describe how capacity is requested, shared, scaled and accounted for.^[ref]

For example, a group running a numerical simulation can request several virtual machines, execute independent runs, save the results and release the virtual machines. Rapid elasticity concerns changing allocated capacity as demand changes; measured service records usage such as processor time or storage. A physically distributed system can have a single operator: physical distribution and administrative control answer different questions.

Peter Mell coauthored The NIST Definition of Cloud Computing by Peter Mell and Timothy Grance in 2011. The publication identifies on-demand self-service, broad network access, resource pooling, rapid elasticity and measured service as essential characteristics.^[ref]

The classification separates what service a consumer controls from how it is deployed. Infrastructure, platform and software services expose different management boundaries, while public, private, community and hybrid deployments describe organizational arrangements. A service can therefore be publicly accessible without giving its consumers control of the underlying operating systems.