A cloud can be private or public. A public cloud is owned and maintained by a cloud
service provider, such as Amazon Web made available to the general public
or industry group. A private cloud is operated solely for an organization: It may be
managed by the organization or a third party arid may exist on or off premise. Like public
clouds, private clouds are able to allocate storage, computing power, or other resources
seamlessly to provide computing resources on an as-needed basis. Companies that want
flexible IT resources and a cloud service model while retaining control over their own IT
infrastructure are gravitating toward these private clouds. (See the chapter-ending case
study.)