Cloud Computing is Internet-based computing which provides on demand shared resources, software, and information to computers and devices. It is an evolution from the client-server model, which in turn evolved from the mainframe model. Cloud Computing is a new model of supplying, consuming, and delivering IT services through the Internet and is a result of the ease-of-access to remote computing sites provided by the Internet. (http://en.wikipedia.org)
Cloud Computing customers don't have to raise the capital to purchase, manage, maintain, and scale the physical infrastructure required to handle drastic traffic fluctuations. Instead of having to invest time and money to keep their sites working, they will simply pay for the resources they use, as they use them. This particular characteristic of cloud computing—its elasticity—means that customers no longer need to predict traffic, but can promote their sites aggressively and spontaneously. Engineering for peak traffic becomes a thing of the past. (http://cloudcomputing.sys-con.com)
Going back to the history of Cloud Computing, this concept dates back to 1960s, when John McCarthy stated that "computation may someday be organized as a public utility". Almost all the modern day characteristics of Cloud Computing (elastic provision, provided as a utility, online, illusion of infinite supply), the comparison to the electricity industry and the use of public, private, government and community forms was thoroughly explored in Douglas Parkhill's, 1966 book, "The Challenge of the Computer Utility". (http://en.wikipedia.org)
The actual term "cloud" borrows from telephony in that telecommunications companies, who until the 1990s primarily offered dedicated point-to-point data circuits, began offering Virtual Private Network (VPN) services with comparable quality of service but at a much lower cost. The cloud symbol was used to denote the demarcation point between that was the responsibility of the provider from that of the...