Cloud computing is based on five attributes: multitenancy (shared resources), massive scalability, elasticity, pay as you go, and self-provisioning of resources.

1) Multitenancy (shared resources)

Cloud computing is based on a business model in which resources are shared (i.e., multiple users use the same resource) at the network level, host level, and application level.

2) Massive scalability

Although organizations might have hundreds or thousands of systems, cloud computing provides the ability to scale to tens of thousands of systems, as well as the ability to massively scale bandwidth and storage space.

3) Elasticity

Users can rapidly increase and decrease their computing resources as needed, as well as release resources for other uses when they are no longer required.

4) Pay as you go

Users pay for only the resources they actually use and for only the time they require them.

5) Self-provisioning of resources

Users sell-provision resources, such as additional systems (processing capability, software, storage) and network resources.