What is a cloud?

Clouds are advanced computational architectures that use virtualization and automation to allocate key resources whenever, wherever, and to whatever extent they’re needed. Imagine a cloud-based service suddenly needs more storage due to a demand spike. The cloud will detect that spike and automatically allocate more storage to the service immediately. Then, when the demand level falls, that storage can be reassigned to a different service. This is normally a responsibility of the IT department and can be challenging to manage.

Because clouds use predefined policies to govern most of what they do, they are incredibly responsive to dynamic situations and can simultaneously support many different kinds of services. Each cloud service can scale up (or down) far more quickly and easily than it could in a traditional architecture.

Public cloud providers lease the use of their clouds to clients for many different purposes. Those clients can then migrate some (or all) of their applications to the cloud and access them over the Internet — eliminating many of the costs and complexities they would normally face managing the applications themselves, while still receiving all the value.

One particularly good example of cloud-friendly applications: Email and Collaboration.