Server Model

The client-server model is the standard approach to the distribution of tasks within a network. Tasks are distributed via servers on different computers and can be requested of them when needed by multiple clients to solve their own tasks or parts. The tasks may be to standard tasks (E-mail, E-mail reception, Web access, etc.) or specific tasks of a software or program. An object is called in client-server model as a service.

A server is a program that provides a service (service). As part of the client-server concept, another program, the client, to use this service. The communication between client and server is dependent on the service, that is, the service determines which data is exchanged between the two. The server is on standby at all times to respond to the touch of a client can. Unlike the client actively requests a service, the server will behave passively and waits for requests. The rules of communication for a service (format, call the server, meaning the data exchanged between the server and client data), are defined by a specific protocol for the service.

Clients and servers can run as programs on different computers or on the same computer. In general, the concept can be extended to a group of servers (software), which offers a set of services. Examples: Mail server, (Enhanced) Web server, application server, database server.

Since running usually collected in practice this server to specific computers, it has become customary to refer to these computer itself as a server. The same examples: mail server, web server, application server, database server.