AN INTRODUCTION TO NETWORKS

Computers have now become a necessity. They are no longer sophisticated machines on which only highly qualified engineers can work. In almost every office today you find at least one PC. The reason is simple. We are moving into the age of communication and information. Competition has become very stiff and every business house, big or small, needs to know what is happening inside and around it as of the last minute. The only solution in such a situation is the computer. Today, even the computer by itself is not enough. Imagine a situation in a big manufacturing organization. There are a number of computers in the factory and a number of them in the office. If the Vice-President wants to know the latest data on production, can he afford to wait until someone copies the information from the factory on a floppy, bring it to the office, load it into the computer there, process it and then give the information to the Vice President? By then, several hours would have passed and the need for the information may no longer be there or, worse still, some vital decision could not have been taken due to lack of information on time.

The solution to this problem arrived a few years ago in the form of networks. Network means that many computers are linked together through some means so that data can be passed between them at any given Time. This effectively means that all the computers linked through a network are able to share resources. These resources could be high-performance, high-speed printers and large hard disks.

Let us make this a little clearer. Some years ago, to book a ticket for a train, we had to stand in a long queue (the one meant for our train only), wait for hours and then get a ticket. And we were never sure of a return journey ticket. Today, the scene is different. We can walk into the reservation complex, stand at any counter and book our ticket almost instantly. Also, we can get our return journey ticket, confirmed, at (he same time.

Networking has made this possible. The Indian Railways have large databases at every major reservation complex. Several terminals are connected to it locally (in the same city). Every time a reservation is done, the database is updated. What is more reservation clerk from a different city, say Delhi, can access the database in any other city, say Madras, and book a ticket for someone from that city. All these databases are linked through a fantastic network of telephone lines.

All this points to one important thing, Network, connect computers not only in the same building or city, but also across different cities and even different countries. Networks which connect computers within a small area are called LANs (Local Area Networks), those which connect computers in different areas of the same city are called MANs (Metropolitan Area Networks) and those that connect computers in different cities or even countries are called WANs (Wide Area Networks).