The Internet and the World Wide Web

The origins of the internet trace to ARPANET, a project funded by the U.S. Department of Defense's Advanced Research Projects Agency, or ARPA, to connect research computers across different institutions using a novel technique called packet switching, in which data is broken into small packets that can travel independently across a network and be reassembled at their destination, a concept developed independently by Paul Baran at the RAND Corporation and Donald Davies at the UK's National Physical Laboratory in the 1960s. ARPANET's first successful connection, linking a computer at UCLA to one at the Stanford Research Institute, was established on October 29, 1969, under a project led by Lawrence Roberts, though the system famously crashed after only the first two letters of the intended message "LOGIN" were transmitted. By 1971, ARPANET connected around two dozen research sites across the United States, and that year programmer Ray Tomlinson, working at contractor Bolt Beranek and Newman, sent the first networked email message and chose the @ symbol to separate a user's name from their host machine, a convention still used in every email address today.