Cloud computing is Internet-based computing, whereby shared resources, software and information are provided to computers and other devices ondemand. It is a paradigm shift, following the shift from mainframe to client–server in the early 1980s. Cloud computing describes a new consumption and delivery model for IT services, one based on the Internet. It typically involves the provision of dynamically scalable and often virtualised resources as a service over the Internet. It is a by-product and consequence of the ease-of-access to remote computing sites provided by the Internet.