2. Introduction to Communication Data communication is the process of sending and receiving data electronically from one computer or similar device to another. Linking one computer to another permits the power and resources of that computer to be tapped. It also makes possible the updating and sharing of data at different locations. Computers that are located in the same room or office building, can communicate data through a direct cable link. Computers located far away use a special form of data communication – telecommunication or telegraph.

3. Nuts and Bolts of a Network A network is any collection of independent computers that communicate with one another over a shared network medium.

4. Applications of Data Communication and Computer Networks Internet Teller and point-of-sale terminals Air Traffic control & Ticket reservation Railway reservation systems, and hotel reservation systems Electronic Banking Web Based Learning. Video Conferencing etc.