What is Internet?

The Internet, sometimes called simply "the Net," is a worldwide system of computer networks - a network of networks in which users at any one computer can, if they have permission, get information from any other computer (and sometimes talk directly to users at other computers).

The internet links private PCs, public networks and business networks together using telephone lines to form one vast worldwide network.

Over a billion people used the Internet in 2008. Of these, about 500 million use the Internet at least once a week, making them more-or-less permanent citizens of the Internet population.

Eric Schmidt, the CEO of Google, the world’s largest index of the Internet, estimated the size at roughly over 5 billion gigabytes of data.

Evolution of internet

Time line

1962: J.C.R. Licklider of MIT, first proposed a global network of computers, and moved over to the Defense Advanced Research Projects Agency (DARPA) in late 1962 to head the work to develop it. Leonard Kleinrock of MIT and later UCLA developed the theory of packet switching, which was to form the basis of Internet connections.

1965: Lawrence Roberts of MIT connected a Massachusetts computer with a California computer over dial-up telephone lines. It showed the feasibility of wide area networking, but also showed that the telephone line's circuit switching was inadequate. Kleinrock's packet switching theory was confirmed.

1966: Roberts moved over to DARPA and developed his plan for ARPANET. These visionaries and many more left unnamed here are the real founders of the Internet.

1969: The Internet, then known as ARPANET, was brought online under a contract let by the renamed Advanced Research Projects Agency (ARPA) which initially connected four major computers at universities in the southwestern US (UCLA, Stanford Research Institute, UCSB, and the University of Utah).

By June 1970: MIT, Harvard, BBN, and Systems Development Corp (SDC) in Santa Monica, Cal. were added.

By January 1971, Stanford, MIT's Lincoln Labs, Carnegie-Mellon, and Case-Western Reserve U were added. In months to come, NASA/Ames, Mitre, Burroughs, RAND, and the U of Illinois plugged in. After that, there were far too many to keep listing here.