Cloud computing is increasingly being used for what was known as "on-demand" and "utility computing". The services provided, the APIs and the applications that can be hosted by these Cloud providers have superseded the use of the grid, and are increasingly becoming popular with users.
The Cloud is a paradigm shift, where details are abstracted from the users; they no longer need expert knowledge about using the various technologies and running their applications on service infrastructure. Cloud computing provides a consumption and delivery model for IT services based on Internet, and it typically involves the provision of dynamically scalable and virtualized services.
There services that are provided by various Cloud providers, which include commercial entities, such as Amazon and Google, as well as those that are open-source systems, such as provided by Open Cirrus and Eucalyptus.