There is hardly anyone who lives in a city and has not heard of Internet or used it. It is a fantastic means of communication, education and research. Rapid progress made in the field of information technology has revolutionised the world of communication. The world is gradually shrinking and becoming a global village. Interaction between people of all the countries has become more frequent than ever before. The widespread and effective use of computers in the field of telecommunications has made the world a smaller place to live in. ISD, FAX, Electronic Mail, Paging Service and now Internet — all are the gifts of this revolution. Internet has aroused much interest in recent days, as it has become a very powerful medium of communication. But what is Internet and how does it operate? Internet is the world’s largest computer network. A computer network is basically a bunch of computers connected together by some means, usually telephone links. It is just like a radio or TV networks that can link various radio or TV stations so that they can share a common programme. The major difference is that in a TV network is that it is one-way communication, and the same information or programme is sent to all stations. In a computer network, a message is usually routed to a particular computer. Some computer networks have a central computer and a group of remote computers that are linked to it — for example, the centralised railways reservation system links many terminal counters to a centralised computer. In Internet, any computer on the network can communicate with any other computer. Truly speaking, the Internet is not really a network; it is a network of networks — all freely exchanging information. Through Internet, people from all countries can now share information, ideas, stories, data and opinions — the functions that were carried out by letters, telephones and other modes of communication so far. It has become the fastest and most reliable way to exchange information. For example, during the 1991 Soviet (present day Russia) coup, a tiny Internet network provided all the information to the rest of the world, when all other communication systems were closed. Medical researchers all over the world use the Internet to establish and maintain databases of rapidly changing data. The Internet facilities are provided through a large number of servers. Listing all the services would make the list exhaustive. For example, electronic mail is the most widely used Internet service. Electronic mailing lists enable a person to join in group discussions and communicate with people over the Net. Online chat, information retrieval, bulletin boards, games and gossip (challenging other players who can be anywhere in the world) are some other kind of Internet services that are available. India’s access to the Internet has ushered in a new phase of computer communication in the country. Originating as a small electronic community in the American Defence Department as a way for military researchers to contact each other, Internet is now the world’s largest electronic network.