Today, the internet is made up of more than 40,000 different networks. By the time the ARPANET was decommissioned in 1990, it was just one of many networks that comprised the internet. This map shows the location of ARPANET and CSNET nodes (labeled 'Phonenet'), which after 1983 communicated with each other using TCP/IP. One of the first new networks to connect to the new internet was CSNET, which was funded by the National Science Foundation to link computer science departments across the country. But the new standard paved the way for much faster network growth by lowering the barrier to entry for new networks. The switch to TCP/IP didn't make much difference from a user perspective - applications like email and Telnet worked about the same as they had before. On January 1, 1983, the ARPANET switched to using TCP/IP, marking the birth of the modern internet. These standards specified the basic format of data packets transmitted across the internet. The result was a set of standards known as TCP/IP.

They decided that the network should be reorganized as a decentralized 'network of networks.' Under this scheme, different networks would be controlled by different organizations, but all the networks able to communicate using shared standards, forming a shared 'internet.' The military asked the computer scientists Robert Kahn and Vint Cerf to develop new networking standards to make this possible. But network operators realized that a centralized network would eventually become unmanageable if it continued to grow. Originally, the entire ARPANET was managed by the military.

Internet highways