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The Internet

While people at work and at home were scurrying to sign up with an online software program, the Internet began to expand beyond its exclusive service as a military function.

One of the Internet's first stops after its military service was in educational institutions. Universities found the Internet especially useful in exchanging research data, ideas, and papers and began exchanging files, data, and findings with other campuses worldwide.

Researchers, however, did not need to set up separate computers to host their data or to serve as a common place to store the information; they already had powerful computers that were connected to the Internet. What was needed, however, was a way to host the data and an established protocol for requesting and receiving information in an organized and efficient manner. Server computers called daemons became the hosts for an Internet protocol. The first daemons were mail and file transfer protocols (FTPs). The FTP daemon waited for the user to request a file. When a file was requested, the daemon started the processes necessary to answer a request. Somewhat like the postal worker who sorts snail mail, the mail daemon waited for mail to arrive, processed that mail, and then forwarded it to a local mailbox or a remote site, where it was delivered to the user.

The idea of an interconnected computer network capable of supporting multiple users with simultaneous access to the same information had long been proposed by scientists who recognized its research potential even before technology made it possible.

The evolution of the Internet dates from the 1960s, with the development of packet-switched networks-messages fragmented into smaller parts. These subparts, or packets, were discrete data units routed and reassembled at the other end of a transmission, permitting several users to share the same connection.

Packet-switched networks took computing from a client/server model to peer-to-peer networks, a development that would ultimately replace the large, centralized mainframe systems with the decentralized systems represented by today's PCs.

In 1969 an early packet-switched network was implemented at the U.S. Department of Defense's Advanced Research Projects Agency (DARPA). In 1982 the ARPANET, as it was called, replaced its original Network Control Protocol (NCP) with the Transmission Control Protocol (TCP) and Internet Protocol (IP). Used together, the TCP/IP suite of communications protocols connects a set of networks, now widely referred to as the Internet.

In the early 1980s, a meeting of DARPA, the National Science Foundation, and scientists from various universities yielded the development of the Computer Science Research Network (CSNET). CSNET and ARPANET were later connected through a gateway called the VAN (Value Added Network). The VAN, coupled with free access to TCP/IP, heralded the beginning of what is now known as the Internet.

Client/server architectures such as the user-created UNIX User Network (Usenet) implementing the Unix-to-Unix Copy Protocol (UUCP) and the Because It's Time Network (BITNET) also emerged in the early 1980s as homegrown alternatives to ARPANET. These networks used off-the-shelf technology in innovative ways, and their users, initially university researchers, have grown into sizable, diverse populations who exchange e-mail, engage in wide-ranging, free-style discussions and subscribe to a countless number of subject areas.

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