Typically, a server provides specific functions to client computers on the network. These functions are called network serverices. Popular network operating systems like Novell NetWare, Microsoft LAN Manager, AppleShare and Banyan Vines provide some, if not all, of the network services listed below.
File services allow users to share information and resources over a network. For example, a student may want to access the card catalog located on the library's computer or use a site-licensed application program. A faculty member may want to look up a student's performance from the previous semester. These tasks are accomplished through file services. File servers normally require a large amount of storage capacity.
Database servers are similiar to file servers, but are optimized for working with database files and have the added capability of being able to provide specific information instead of sending the entire file.
In the strict definition of an application server, the processing of a command can be started from a client computer, the processing is done on server and the results from the command are sent back to the client computer. The command could be something very simple or a very complicated program. This type of server is sometimes called a Terminal Emulation server.
A broader definition for an application server would include the concept of servers that store the programs but then send the entire program to the client and the client does all of the processing.
Print services allow users to print documents to a printer. Some networks are set up so that computers print to a print queue on a server. The server then handles the printing, allowing the user to continue his work even if the print job hasn't finished. A print server is especially useful in classroom and lab scenarios where multiple students send print jobs simultaneously.
File and Print services are frequently grouped together because they are the most common services provided.
Mail services allow users to send and receive electronic mail. Electronic mail facilitates communication between members of the computing environment. Using an e-mail package, a teacher can schedule a conference with a student or parent, send files to other departments and disseminate information to an entire student body.
Communication/Remote Access Server
Communication services let remote users dial-in to the network, using a modem, to access other network services. For example, a parent might dial-in from work to his child's school network to send an e-mail to his child's teacher. Communication services also let students and teachers dial-out to the Internet, electronic bulletin boards and other services such as AppleLink® or Compuserve®.
Proxy Server The Proxy Server by itself does not constitute a firewall and does not eliminate the need for one.