Cloud computing metaphor: the group of networked elements providing services need not be individually addressed or managed by users; instead, the entire provider-managed suite of hardware and software can be thought of as an amorphous cloud. Created by Sam Johnston using OmniGroup's OmniGraffle and Inkscape.
In 1966 Canadian technologist Douglas Parkhill issued a book entitled The Challenge of the Computer Utility. In this work Parkhill predicted and explored features of cloud computing that became widely established by the second decade of the twenty-first century. These features included elastic provision, provision as a utility, online, illusion of infinite supply, the comparison to the electricity industry and the use of public, private, government, and community forms.