How did the Internet begin?

In 1969, the Department of Defense set up an experimental network called ARPANET (Advanced Research Projects Agency Network). The network was used to research, develop and test networking technologies. The original network connected four host computers at four separate universities throughout the United States, enabling users to share resources and information.

ARPANET functioned as a backbone network, allowing smaller local networks to connect to the backbone. Once these smaller networks were connected to the backbone, they were in effect connected to each other.

In 1973, ARPANET went beyond the boundaries of the United States by making its first international connections to England and Norway.

In 1986 a faster backbone was created by the National Science Foundation. By 1989 there were over 10,000 host computers connected to the Internet, or "network of networks". And because the NSF Netowrk was so successful, ARPANET was dissolved in 1990 and many of the sites connected to it were absorbed by the NSFNET.