关键区别：客户机是一个计算机程序，它向另一个程序发送请求以执行其操作。服务器是接收和响应程序，它处理客户机程序的请求并使客户机能够执行其操作。

服务器作为一个系统在计算机网络中工作，并对另一个程序发送的请求作出响应，从而提供网络服务。大多数情况下，服务器都是在特定的专用计算机上操作和运行的，因此就其所处理的网络而言，该计算机被称为“服务器”。单个中央服务器可以同时控制和操作多个客户端。

A server is essentially a part of a network system which is known as client-server architecture. Within this model the client serves the role of an initiator while the server effectively serves to process the requests send by the client. The computers connected within a network are also able of hosting servers. Again a computer may also run several servers and connect to the required one accordingly. A server is typically a socket listener that can serve numerous users at a time. This client-server architecture operates to serve public users through internet or private users dedicated to some specific organization or network. The common operating servers in various networks are web server, file server, mail server, database server and range of other server.

A variety of computing operati*** undergo the usage of a server. The server works as the central controller of data from where the co-ordinati*** network machines or workstati*** access the data and this kind of server is thereby termed as application server. This effectively serves the purpose of data streamlining. 

Internet in the similar way is a stack of server where a single request for a web page is processed through a channel of protocols which are satisfied by a number of servers. This may involve modem, routers, domain name server and multiple other servers to process a singular web page request.

虽然任何一台计算机都能够扮演网络服务器的角色，但它可能无法提供专用服务器的有效功能。专用服务器是在高端特色样机的基础上设计的，能够提供卓越的高性能。这些专用服务器支持大容量存储、高性能ram和高速cpu、容错和其他特定功能。

A client is also a computer program which sends requests to its resource end that is a server and accepts the processed request to perform its operati***. However, the client program and the server program can effectively run on the same computer and in such cases the client connects with the server through inter-process communication. Clients are the initiators of such connecti*** where servers wait for potential clients to connect. Previously the term was denoted to devices that would act as dumb terminals and depend on remote computers connected through a network to perform their programs. 

Client devices can be classified as fat clients, thin clients and hybrid clients. A fat client or thick client is less dependent on server for they can perform their data processing operati*** without essential dependency over a server. Personal computer or a CAD running computer is paradigms or fat clients. A thin client is a device that uses web application to perform its operati***. It approaches an application server to work its operation. Hybrid client is the combination of these two types of clients.