Server

A server in computing is:

   * A computer software application that carries out some task on behalf of
     users. This is usually divided into file serving, allowing users to
     store and access files on a common computer; and application serving,
     where the software runs a computer program to carry out some task for
     the users. This is the original meaning of the term.

   * The term is now also used to mean the actual computer on which the
     software runs. Originally server software would be located on a
     mainframe computer or minicomputer. These have largely been replaced by
     computers built using a more robust version of the microprocessor
     technology that is used in personal computers, and the server term was
     adopted to describe such microprocessor based machines.

Server Hardware

A Server computer shares its resources, such as peripherals and file storage
with the users' computers, called clients, on a network. It is possible for
a computer to be a client and a server simultaneously, by connecting to
itself in the same way a separate computer would.

Many new devices now come with server capabilities. The X-Internet, Web
Services, and Microsoft's .NET initiative all work to make even the smallest
system a server.

Many large enterprises employ numerous servers to support their needs. A
collection of servers in one location is often referred to as a server farm.

Server Operating Systems

The rise of the microprocessor based server was facilitated by the
development of several versions of Unix to run on the Intel microprocessor
architecture, including Solaris, Linux and FreeBSD. The Microsoft Windows
series of operating systems also now includes server versions that support
multitasking and other features required for servers, beginning with Windows NT.

Historical Note

Mainframes and minicomputers were originally accessed using dumb terminals,
which were unable to carry out any significant processing. This largely
ended with the widespread use of personal computers by users.