Client is a
computer that gets information from another computer called
server in the context of
client–server model of
computer network
A computer network is a collection of communicating computers and other devices, such as printers and smart phones. In order to communicate, the computers and devices must be connected by wired media like copper cables, optical fibers, or b ...
s. The server is often (but not always) on another computer system, in which case the client accesses the service by way of a network.
A client is a
program that, as part of its operation, relies on sending a request to another program or a computer hardware or software that accesses a service made available by a server (which may or may not be located on another computer).
For example,
web browsers are clients that connect to
web servers and retrieve
web pages for display.
Email clients retrieve
email from
mail servers.
Online chat uses a variety of clients, which vary on the chat protocol being used.
Multiplayer video games or
online video games may run as a client on each computer.
The term "client" may also be applied to computers or devices that run the client software or users that use the client software.
A client is part of a
client–server model, which is still used today. Clients and servers may be computer programs run on the same machine and connect via inter-process communication techniques. Combined with
Internet sockets, programs may connect to a service operating on a possibly remote system through the
Internet protocol suite. Servers wait for potential clients to initiate connections that they may accept.
The term was first applied to
devices that were not capable of running their own stand-alone programs, but could interact with remote computers via a network. These
computer terminals were clients of the
time-sharing mainframe computer.
Types
In one classification, client computers and devices are either
thick clients,
thin clients, or
diskless nodes.
Thick
A ''thick client'', also known as a ''rich client'' or ''fat client'', is a client that performs the bulk of any data processing operations itself, and does not necessarily rely on the
server. The
personal computer is a common example of a fat client, because of its relatively large set of features and capabilities and its light reliance upon a server. For example, a computer running an
art program (such as
Krita or
Sketchup) that ultimately shares the result of its work on a network is a thick client. A computer that runs almost entirely as a standalone machine save to send or receive files via a network is by a standard called a
workstation.
Thin

A ''thin client'' is a minimal sort of client. Thin ''clients'' use the resources of the host computer. A thin client generally only presents processed data provided by an
application server, which performs the bulk of any required data processing. A device using
web application (such as
Office Web Apps) is a thin client.
Diskless node
A ''diskless node'' is a mixture of the above two client models. Similar to a fat client, it processes locally, but relies on the server for storing persistent data. This approach offers features from both the fat client (multimedia support, high performance) and the thin client (high manageability, flexibility). A device running an online version of the
video game
A video game or computer game is an electronic game that involves interaction with a user interface or input device (such as a joystick, game controller, controller, computer keyboard, keyboard, or motion sensing device) to generate visual fe ...
Diablo III is an example of diskless node.
References
{{Download managers
Peer-to-peer computing