Cloud computing

Cloud Computing and Grid Computing are emerging technologies but what are the difference

Cloud Computing

At a basic level, cloud computing is simply a means of delivering IT resources as services. Almost all IT resources can be delivered as a cloud service: applications, compute power, storage capacity, networking, programming tools, even communications services and collaboration tools.
Cloud computing began as large-scale Internet service providers such as Google, Amazon, and others built out their infrastructure. An architecture emerged: massively scaled, horizontally distributed system resources, abstracted as virtual IT services and managed as continuously configured, pooled resources. This architectural model was immortalized by George Gilder in his October 2006 Wired magazine article titled “The Information Factories.” The server farms Gilder wrote about were architecturally similar to grid computing, but where grids are used for loosely coupled, technical computing applications, this new cloud model was being applied to Internet services.

“In this architecture, the data is mostly resident on servers
‘somewhere on the Internet’ and the application runs on
both the ‘cloud servers’ and the user’s browser.”
—Eric Schmidt in ‘Information Factories’ by G. Gilder

Sun Cloud computing primer

Grid Computing

Grid computing (or the use of a computational grid) is the application of several computers to a single problem at the same time – usually to a scientific or technical problem that requires a great number of computer processing cycles or access to large amounts of data.
Grid computing depends on software to divide and apportion pieces of a program among several computers, sometimes up to many thousands. Grid computing can also be thought of as distributed[citation needed] and large-scale cluster computing, as well as a form of network-distributed parallel processing[citation needed]. It can be small -- confined to a network of computer workstations within a corporation, for example -- or it can be a large, public collaboration across many companies or networks.