There wasn't just one person who invented the internet.
However, the persons who invented the Internet did have something in common. They all worked for the Defence Advanced Research Project Agency (DARPA), an agency of the United States Department of Defense.
DARPA was established in the late 1950's to protect the national security interests of the United States from being adversely effected by technological surprises, and to develop strategic technological superiority over adversaries.
The development of this superiority included, but was not limited to, the computer sciences, material sciences, neurosciences, physics, engineering, chemistry, biology, and medicine.
In 1962, DARPA established the Information Processing Techniques Office (IPTO) to interconnect computers at Cheyenne Mountain Air Force Station with those located at the Pentagon and the Strategic Air Command.
An associate professor at MIT, J.C.R. Licklider, was appointed as first Director of the IPTO. He majored in physics, mathematics and psychology at Washington University.
Among those who invented the Internet, it was Licklider who envisioned a worldwide network of people sharing information.
At that time, data communication occurred between a main computer and remote terminals as an enclosed network. There was no "inter-networking".
The word "internet" is the abbreviation of the term "inter-networking".
It wasn't until the 1970's that a system was developed that could join multiple networks (government, academic, commercial, private, and public) together to transmit and share information despite the structural differences between them.
This system was developed by Lawrence G Roberts and a team of scientists at DARPA, considered to be among those contributors who invented the internet. The system, known as "packet switching", allowed for the rapid storing and transmitting of blocks of information or "packets" between networks.
The interconnecting of networks required rules and regulations, which became the "transmission control protocol" (TCP) and the "internet protocol" (IP), also known jointly as TCP/IP.
It wasn't until the 1990's that the Internet gained global popularity with the inventions of the World Wide Web, electronic mail, and various wireless and optical technologies.
Although these inventions and technologies contributed to the Internet's use, their inventors were not considered to be among those who invented the Internet.
Over the past decade, the majority of computer networks are now interconnected through the Internet, which currently has an estimated 2 billion users.
As populous developing nations gain accessibility to the Internet, it's expected users will triple within the next few years.
Source: www.darpa.mil Graphics: Ilco, Wyris, Mmagallan