Клиент–сервер моделі: Нұсқалар арасындағы айырмашылық

The '''client/server model''' is a [[computing]] model that acts as a [[distributed application]] which partitions tasks or workloads between the providers of a resource or service, called [[server (computing)|server]]s, and service requesters, called [[client (computing)|client]]s.<ref>{{cite web|url=http://java.sun.com/developer/Books/jdbc/ch07.pdf|publisher=Sun Microsystem|title=Distributed Application Architecture|accessdate=2009-06-16}}</ref> Often clients and servers communicate over a [[computer network]] on separate hardware, but both client and server may reside in the same system. A server machine is a host that is running one or more server programs which share their resources with clients. A client does not share any of its resources, but requests a server's content or service function. Clients therefore initiate communication sessions with servers which await incoming requests.▼

[[File:Client-server-model.svg|thumb|Schematic clients-server interaction.]]▼

The ''client/server'' characteristic describes the relationship of cooperating programs in an application. The server component provides a function or service to one or many clients, which initiate requests for such services. A notable example of this is the way [[OpenGL]] treats the video card of a computer as a server, with the actual application making rendering requests to it. This model is further solidified with the [[GLSL|OpenGL Shading Language]], with the user writing small programs that live in video memory, and are requested from the main program through the graphics driver.▼

''Functions'' such as email exchange, web access and database access are built on the client/server model. Users accessing banking services from their computer use a web browser client to send a request to a web server at a bank. That web server runs a program which may in turn, forward the request to its own database client program, which sends a request to the bank's database server (which runs on another computer) to retrieve the account information. The balance and transaction records are returned to the bank database client, which in turn serves it back to the user's web browser client, displaying the results to the user.▼

The client–server model has become one of the central ideas of [[network computing]]. Many business applications being written today use the client–server model, as do the Internet's main application protocols, such as [[HTTP]], [[SMTP]], [[Telnet]], and [[Domain Name System|DNS]]. ▼

The interaction between client and server is often described using [[sequence diagram]]s. The [[Unified Modeling Language]] has support for sequence diagrams.▼

Specific types of clients include [[web browser]]s, [[email client]]s, and [[online chat]] clients.▼

Specific types of servers include [[web server]]s, [[ftp server]]s, [[application server]]s, [[database server]]s, [[name server]]s, [[mail server]]s, [[file server]]s, [[print server]]s, and [[terminal server]]s. Most [[web service]]s are also types of servers.▼