Server (computing)

Usage in information technology.

In hardware

A server is a computer that has been set aside to run a specific server application. For example, when the software Apache HTTP Server is used as the web server for a company's website, the computer running Apache is also called the web server. Server applications can be divided among server computers over an extreme range, depending upon the workload.

Server is also used as a designation for computer models intended for use in running server applications under heavy workloads, also called operating units often unattended and for an extended period of time. While any workstation computer is capable of acting as a server, a server computer usually has special features intended to make it more suitable. These features can include a faster CPU, faster and more plentiful RAM, and larger hard drives. More obvious distinctions include redundancy in power supplies, network connections, and storage devices as well as the modular design of so-called Blade servers often used in server farms.

A server appliance refers to network-connected computer appliances or "appliance hardware" that provide specific, dedicated applications to a network. Use of the term appliance indicates the marriage of software and hardware in a single system that is not heavily customizable such as Google Search Appliance. Such appliances are expected to work out-of-the-box with little customization and sometimes remain the sole property of the company that produced them. The simplest appliances include switches, routers, gateways, and print servers.

In software

Server used as an adjective, as in server operating system, refers to the product's ability to handle multiple requests, and is said to be "server-grade". A server operating system is intended or better enabled to run server applications. The differences between the server and workstation versions of a product can vary from the removal of an arbitrary software limits due to licensing, as in the case of Windows 2000, or the addition of bundled applications as in Mac OS X Server.