Servers have software installed that enables them to provide services, such as email or web pages, to clients. Each service requires separate server software. For example, a server requires web server software to provide web services to the network.
In a client/server network, the client requests information or services from the server. The server provides the requested information or service to the client. Servers on a client/server network commonly perform some of the processing work for client machines, for example, sorting through a database before delivering only the records requested by the client. This provides for centralized network administration, which makes it easy to determine who controls resources on the network. Resources are controlled by a centralized network administration.
A computer with server software can provide services simultaneously to one or many clients. Additionally, a single computer can run multiple types of server software. In a home or small business, it may be necessary for one computer to act as a file server, a web server, and an email server. In a corporate environment employees may access a single computer in the company which acts as an email server. This email server is used only to send, receive, and store email. The email client on an employee computer issues a request to the email server for any unread email. The server responds by sending the requested email to the client.
A single computer can also run multiple types of client software. There must be client software for every service required. With multiple client software installed, a client can connect to multiple servers at the same time. For example, a user can check email and view a web page while instant messaging and listening to Internet radio.
A client/server model makes it easy to determine who controls resources on the network by providing central network administration. The network administrator implements data backups and security measures. The network administrator also controls user access to the network resources. All of the data on the network is stored on a centralized file server. A centralized print server manages shared printers on the network. Each user must provide an authorized username and password to gain access to network resources that each person is permitted to use.