Definition and Brief History of the Internet
Definition
A large computer network linking smaller computer networks worldwide.
Brief History
The Internet evolved from a secret feasibility study conceived by the U.S. Dept. of Defense in 1969 to test methods of enabling computer networks to survive military attacks, by means of the dynamic rerouting of messages. As the ARPAnet (Advanced Research Projects Agency network), it began by connecting three networks in California with one in Utah—these communicated with one another by a set of rules called the Internet Protocol (IP). By 1972, when the ARPAnet was revealed to the public, it had grown to include about 50 universities and research organizations with defense contracts, and a year later the first international connections were established with networks in England and Norway. A decade later, the Internet Protocol was enhanced with a set of communication protocols, the Transmission Control Program/Internet Protocol (TCP/IP), that supported both local and wide-area networks. Shortly thereafter, the National Science Foundation (NSF) created the NSFnet to link five supercomputer centers, and this, coupled with TCP/IP, soon supplanted the ARPAnet as the backbone of the Internet. In 1995, however, the NSF decommissioned the NSFnet, and responsibility for the Internet was assumed by the private sector. Fueled by the increasing popularity of personal computers, e-mail, and the World Wide Web (which was introduced in 1991 and saw explosive growth beginning in 1993), the Internet became a significant factor in the stock market and commerce during the second half of the decade. By 2000 it was estimated that the number of adults using the Internet exceeded 100 million in the United States alone.
