1969: On Sept. 2, two computers at University of California, Los Angeles, exchange meaningless data in first test of Arpanet, an experimental military network. The first connection between two sites — UCLA and the Stanford Research Institute in Menlo Park, Calif. — takes place on Oct. 29, though the network crashes after the first two letters of the word “logon.”
1972: Ray Tomlinson brings e-mail to the network, choosing “at” symbol as way to specify e-mail addresses belonging to other systems.
1974: Vint Cerf and Bob Kahn develop communications technique called TCP, allowing multiple networks to understand one another, creating a true Internet.
1983: Domain name system is proposed. Creation of suffixes such as “.com,” “.gov” and “.edu” comes a year later.
1988: One of the first Internet worms, Morris, cripples thousands of computers.
1989: Quantum Computer Services, now AOL, introduces America Online, beginning an expansion that would connect nearly 27 million Americans online by 2002.
1993: Marc Andreessen and colleagues at the University of Illinois create Mosaic, the first Web browser to combine graphics and text on a single page, opening the Web to the world with software that is easy to use.
1994: Andreessen and others on the Mosaic team form a company to develop the first commercial Web browser, Netscape.
1999: World Internet population surpasses 250 million.
2002: World Internet population surpasses 500 million.
2004: Mark Zuckerberg starts Facebook as a sophomore at Harvard University.
2005: Launch of YouTube.
2006: World Internet population surpasses 1 billion.
2008: World Internet population surpasses 1.5 billion.
