When was the internet invented?
The internet grew out of ARPANET, a US network that sent its first message in 1969. Many date the modern internet to January 1, 1983, when ARPANET adopted the TCP/IP protocols still used today.
ARPANET was funded by the US Department of Defense's Advanced Research Projects Agency. On October 29, 1969, a computer at UCLA sent the first message to one at Stanford. The system crashed after the first two letters, LO, of the word LOGIN. By the end of 1969, four universities were connected.
In the 1970s, computer scientists Vint Cerf and Bob Kahn developed TCP/IP, a common set of rules that allowed different networks to connect and talk to each other, forming a network of networks. ARPANET switched to TCP/IP on January 1, 1983, which is often called the internet's birthday.
The internet goes public
The internet was mostly used by universities and researchers until the 1990s, when commercial restrictions were lifted and the World Wide Web made it easy to use. Today, more than five billion people are online, about two-thirds of the world's population.
Did You Know?
Email predates the modern internet. Ray Tomlinson sent the first network email on ARPANET in 1971 and chose the @ symbol to separate names from computers.