Server (computer)
A server is a computer that is used to "serve" content to other computers. There are many types of servers, including file servers, web servers, and database servers. A server responds to the requests of a client. The client communicates with a server by using a protocol to request and receive information.
A server can consist of any sort of computer, from an personal computer to a multi-thousand dollar server. A server is primarily defined by its function and software rather than any particular hardware.
Components
The primary components of a server are similar to the primary components of a personal computer or most other computers. However, a server is generally designed to do a single task as efficiently as possible, whereas most other computers are designed to be general-purpose.