3.8 GRID (CLOUD) COMPUTING

Grid computing refers to providing access to computing resources distributed over a wide area network (WAN). In that sense, a grid computer is a collection of a large number of processors distributed over a wide geographic area. A grid computer can handle large-scale computational problems such as N-body simulations, seismic simulations, and atmospheric and oceanic simulations. Compared with cluster computing, a grid computer is a large cluster where the LAN is now replaced with a WAN, such as the Internet. The problems at the back of the chapter summarize the main differences between cluster and cloud computing.

Some of the applications implemented using cloud computing include

• peer-to-peer (P2P) computing;
• software as a service, like Google Apps, Google Calendar, and Google mail;
• mass storage; and
• web applications and social networks.