The global TCP/IP public internetwork that originated in the ARPANET project of the U.S. Department of Defense in the 1970s.
The original purpose of ARPANET was to create a wide area network (WAN) that would allow researchers at various defense and civilian research agencies to communicate with each other and to collaborate on projects.
When ARPANET grew larger and an increasing number of civilian agencies such as universities and networking companies wanted access to it, administration of the network (now called the Internet) was given to the National Science Foundation (NSF) and then to Internet Network Information Center (InterNIC).
The backbone networks that make up the Internet are owned and managed by private companies, including MCI WorldCom and Sprint. These companies often share physical lines and often lease lines from Regional Bell Operating Companies (RBOCs). Backbone lines on the Internet are linked at points called Network Access Points (NAPs), where Internet service providers (ISPs) can exchange traffic. Examples of NAPs include MCI WorldCom’s “MAE West” NAP in San Jose, California, and the company’s “MAE East” NAP in Washington, D.C. An ISP leases a point of presence (POP) connection to a backbone’s network in order to supply individual users and companies with Internet services. See the Web link in this entry for topological and descriptive views of the architecture of the Internet.
The Internet is not owned by any one group; it is a collection of networks and gateways that run a common TCP/IP protocol and that all evolved from ARPANET. Nevertheless, various administrative bodies oversee various aspects of the Internet. These groups include the following:
Although a large number of Internet protocols currently support applications for users of the Internet, these services are constantly evolving, and many are rapidly disappearing as new services emerge. By far the most popular business uses of the Internet are the World Wide Web (WWW) and e-mail. Usenet newsgroups and Internet Relay Chat (IRC) are also popular.