server farm (Web farm, Web server farm)
A server farm is a group of computers acting as servers and housed together in a single location. A server farm is sometimes called a server cluster. A Web server farm can be either (1) a Web site that has more than one server, or (2) an Internet service provider (ISP) that provides Web hosting services using multiple servers.
In a business network, a server farm or cluster might perform such services as providing centralized access control, file access, printer sharing, and backup for workstation users. The servers may have individual operating systems or a shared operating system and may also be set up to provide load balancing when there are many server requests. In a server farm, if one server fails, another can act as backup.
On the Internet, a Web server farm, or simply Web farm, may refer to a Web site that uses two or more servers to handle user requests. Typically, serving user requests for the files (pages) of a Web site can be handled by a single server. However, larger Web sites may require multiple servers.
Web farm is a term that is also simply used to mean a business that performs Web site hosting on multiple servers. Some Web farms allow you to put your own server on their site, a service known as colocation.