According to a definition on Wikipedia, “Cloud computing is the on-demand availability of computer system resources, especially data storage and computing power, without direct active management by the user. The term is generally used to describe data centers available to many users over the Internet.” Simply speaking we can say that cloud computing is the practice of using a network of remote servers which are hosted on the Internet to perform some tasks of storing, managing, and processing data, instead of a local server or a personal computer.