History of the Internet

During the 1960s, the U.S. Department of Defense’s Advanced Research Projects Agency (ARPA, later called DARPA) began an experimental wide area network (WAN) that spanned the United States. Called ARPANET, its original goal was to enable government affiliations, educational institutions, and research laboratories to share computing resources and to collaborate via file sharing and electronic mail. It didn’t take long, however, for DARPA to realize the advantages of ARPANET and the possibilities of providing these network links across the world.

By the 1970s, DARPA continued aggressively funding and conducting research on ARPANET, to motivate the development of the framework for a community of networking technologies. The result of this framework was the Transmission Control Protocol/Internet Protocol (TCP/IP) suite. (A protocol is basically defined as a set of rules for communication over a computer network.) To increase acceptance of the use of protocols, DARPA disclosed a less expensive implementation of this project to the computing community. The University of California at Berkeley’s Berkeley Software Design (BSD) UNIX system was a primary target for this experiment. DARPA funded a company called Bolt Beranek and Newman, Inc. (BBN) to help develop the TCP/IP suite on BSD UNIX.

This new technology came about during a time when many establishments were in the process of developing local area network technologies to connect two or more computers on a common site. By January 1983, all of the computers connected on ARPANET were running the new TCP/IP suite for communications. In 1989, Conseil Europeen pour la Recherche Nucleaire (CERN), Europe’s highenergy physics laboratory, invented the World Wide Web (WWW). CERN’s primary objective for this development was to give physicists around the globe the means to communicate more efficiently using hypertext. At that time, hypertext only included document text with command tags, which were enclosed in <angle brackets>. The tags were used to markup the document’s logical elements, for example, the title, headers and paragraphs. This soon developed into a language by which programmers could generate viewable pages of information called Hypertext Markup Language (HTML). In February 1993, the National Center for Supercomputing Applications at the University of Illinois (NCSA) published the legendary browser, Mosaic. With this browser, users could view HTML graphically presented pages of information.

At the time, there were approximately 50 Web servers providing archives for viewable HTML. Nine months later, the number had grown to more than 500. Approximately one year later, there were more than 10,000 Web servers in 84 countries comprising the World Wide Web, all running on ARPANET’s backbone called the Internet.

Today, the Internet provides a means of collaboration for millions of hosts across the world. The current backbone infrastructure of the Internet can carry a volume well over 45 megabits per second (Mb), about one thousand times the bandwidth of the original ARPANET. (Bandwidth is a measure of the amount of traffic a media can handle at one time. In digital communication, this describes the amount of data that can be transmitted over a communication line at bits per second, commonly abbreviated as bps.)