Characteristics of Cloud Computing
Cloud computing is the delivery of computing resources, such as servers, storage, and software, over the internet instead of from hardware a user owns and maintains directly. The U.S. National Institute of Standards and Technology (NIST) defined five essential characteristics that are still the standard reference point for what actually makes a service 'cloud computing' rather than just remote hosting.
Last updated: 8 September 2026
Key characteristics
On-demand self-service
A user can provision computing resources, such as server capacity or storage, whenever needed through an automated interface, without requiring a human interaction with the service provider.
Broad network access
Cloud resources are available over the internet and can be accessed from a wide range of devices, including laptops, phones, and tablets, using standard mechanisms like a web browser.
Resource pooling
The provider's computing resources are pooled to serve multiple customers at once using a multi-tenant model, with resources dynamically assigned and reassigned according to demand, generally without customers knowing the exact physical location of their data.
Rapid elasticity
Computing capacity can scale up or down quickly, sometimes automatically, to match demand, so a sudden traffic spike can be absorbed without manual reconfiguration and capacity can shrink again once demand drops.
Measured service
Cloud systems automatically monitor and report resource usage, such as storage, bandwidth, or processing time, which allows for the pay-as-you-go billing model most cloud providers use.
Reduced need for owned infrastructure
Because the provider owns and maintains the underlying hardware, customers avoid large upfront capital spending on physical servers and the ongoing cost of maintaining them.
Shared responsibility for security
Security in the cloud is typically split between the provider, who secures the underlying infrastructure, and the customer, who is responsible for securing their own data, access controls, and configurations.
Frequently asked questions
What are the NIST five essential characteristics of cloud computing?
The five characteristics defined by NIST are on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service. These five are what formally distinguish cloud computing from simply renting a dedicated remote server.
What's the difference between IaaS, PaaS, and SaaS?
IaaS (Infrastructure as a Service) provides raw computing resources like virtual machines and storage. PaaS (Platform as a Service) provides a ready-made environment for building and running applications without managing the underlying servers. SaaS (Software as a Service) delivers a complete, ready-to-use application over the internet, such as an email or accounting platform.
Is cloud computing always cheaper than on-premise infrastructure?
Not always. Cloud computing typically reduces upfront capital costs and offers flexibility, but ongoing usage-based costs can exceed the cost of owned infrastructure for large, stable, predictable workloads, which is why many organisations use a mix of both.