Cloud computing involves the provision of computer, component, or a network of virtual resources online. In essence, it is Internet‐based computing, whereby shared resources, software and information are provided online to computers and other devices on demand, like a public utility over the Internet. It is a general term for anything that involves delivering hosted services over the Internet and describes a new concept for IT services. A paradigm from mainframe to client–server that preceded it in the early '80s, it is a byproduct and consequence of the ease-of-access to remote computing sites provided by the Internet.
The term cloud is used as a metaphor for the Internet, based on the earlier models used to depict the telephone network, and its relationship with the Internet in computer network diagrams. Clouds often appear as single points of access for all consumers' computing needs and generally have five essential characteristics: on demand self-service, broad network access, resource pooling, rapid elasticity, and measured service. Typical cloud computing providers deliver common business applications online which are accessed from a web browser, while the software and data are stored on servers.