Research on dividing information into packets and switching them from computer to computer began in the 1960s. The U.S. Department of Defense Advanced Research Projects Agency (ARPA) funded a research project that created a packet switching network known as the ARPANET. ARPA also funded research projects that produced two satellite networks. In the 1970s ARPA was faced with a dilemma: Each of its networks had advantages for some situations, but each network was incompatible with the others. ARPA focused research on ways that networks could be interconnected, and the Internet was envisioned and created to be an interconnection of networks that use TCP/IP protocols. In the early 1980s a group of academic computer scientists formed the Computer Science NETwork, which used TCP/IP protocols. Other government agencies extended the role of TCP/IP by applying it to their networks: The Department of Energy’s Magnetic Fusion Energy Network (MFENet), the High Energy Physics NETwork (HEPNET), and the National Science Foundation NETwork (NSFNET).
In the 1980s, as large commercial companies began to use TCP/IP to build private internets, ARPA investigated transmission of multimedia—audio, video, and graphics—across the Internet. Other groups investigated hypertext and created tools such as Gopher that allowed users to browse menus, which are lists of possible options. In 1989 many of these technologies were combined to create the World Wide Web. Initially designed to aid communication among physicists who worked in widely separated locations, the Web became immensely popular and eventually replaced other tools. Also during the late 1980s, the U.S. government began to lift restrictions on who could use the Internet, and commercialization of the Internet began. In the early 1990s, with users no longer restricted to the scientific or military communities, the Internet quickly expanded to include universities, companies of all sizes, libraries, public and private schools, local and state governments, individuals, and families.