Principles Digital Communication System & Computer Networks (Charles River Media Computer Engineering)

15.2 SERVICES AND APPLICATIONS

The need for a network of computers arises mainly to share the information present in different computers. The information can be transported electronically from one computer to another, obviating the need for physical transportation through floppies or CD-ROMs. In addition, resources can be shared—for example, a printer connected to a computer on the network can be accessed from other computers as well. The services that can be supported on the network are:

Electronic mail: This is the most popular service in computer networks. People can exchange mail and the mail can contain, in addition to the text, graphics, computer programs, and such.

File transfer: A file on one computer can be transferred to another computer electronically.

Remote login: A person at one computer can log in to another computer and access the programs or files on the other computer. For instance, a person using a PC can log in to a mainframe computer and execute the programs on the mainframe.

These are the basic services supported by computer networks. Using these services, many applications can be developed, such as bibliographic services to obtain literature on a specific topic, to search different computers on a network for specific information, to find out where the information is available and then obtain the information, etc.

The three basic services supported by computer networks are: email, file transfer and remote login.