The Internet has become part of everyday life, and it is difficult to imagine a world without it. The Internet as we know it today, however, is quite recent. Let's take time for a quick look at how the Internet came to be.
The Internet has its origins in the Cold War. In 1957, the Soviet Union launched the first satellite, Sputnik. In response, the United States created the Advanced Research Projects Agency, or ARPA. The plan emerged to create a communication network that would not be vulnerable to a nuclear attack. The basic idea was to use a distributed network and break messages into blocks to route over this network.
This specific military network was never built, but ARPA proceeded with working on a network for more general communication purposes, in particular to share research. In 1969, ARPANET was created, connecting computers at four universities across the country.
The network used a packet-switching approach, with messages broken up into arbitrary packets that were routed across the network. By 1974, this protocol was refined as the Transmission Control Program, or TCP. The document describing TCP used the term 'internet' for the first time, as shorthand for 'internetworking.' The term was not yet used to describe the actual network.
ARPANET grew in the next several years, with several other separate networks emerging at the same time, including the Computer Science Network (CSNET). The idea emerged to have multiple networks connected in a network of networks.
In addition to the existing TCP protocol, the Internet Protocol, or IP, was developed to ensure packets of information routed over a network were delivered to the right destination.
In 1982, the combined TCP/IP protocols were adopted as the communication standard for different networks. This is when the term 'Internet' became widely used to describe the concept of a worldwide network or connected networks.
A high-speed backbone for the network was built by the National Science Foundation to connect supercomputing centers. Local networks were allowed to connect to this backbone, and this really made the Internet viable as a way to communicate between different networks. For a number of years, the Internet was mostly used by university researchers and defense contractors, but by the early 1990s, private companies also started using the Internet.
Meanwhile, local networks were developing in other regions, in particular in Europe. These networks also started using TCP/IP, and gradually, the Internet expanded across the globe.
