Cloud computing is a general term for the delivery of hosted services over the Internet. The practice of using a network of remote servers hosted on the Internet to store, manage, and process data, rather than a local server or a personal computer.
Cloud computing is now a days hot topic among IT professionals, vendors, manufacturers and enterprises. IT giants Microsft, Google, Amazon, Apple, IBM and HP all are already in the cloud computing technology. They all are offering software as a service (SaaS), Platform as a service (PaaS) and Infrastructure as a service (IaaS).
Of course, cloud computing is big business: The market was already generating $100 billion a year in 2012. It could be $270 billion by the year 2020.