Cloud computing is a paradigm shift following the shift from mainframe to client server in the early 1980s. Details are abstracted from the users, who no longer have need for expertise in, or control over, the technology infrastructure “in the cloud” that supports them.
Cloud computing describes a new supplement, consumption, and delivery model for IT services based on the Internet, and it typically involves over-the-Internet provision of dynamically scable and oftenvirtualized sources.
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 cloud drawing used in the past to represent the telephone network and later to depict the Internet in computer network diagrams as an abstraction of the underlying infrastructure it represents.
Typical cloud computing providers deliver common business applications online that are accessed from another Web service or software like a Web Browser r, while the sotfware and date are stored on servers.
Most cloud computing infrastructures consist of services delivered through common centers and built on servers. Clouds often appear as single points of access for all consumers’ computing needs. Commercial offerings are generally expected to meet quality of services (QoS) requirements of customers, and typically include SLAs.