Briefly explain how Internet evolved.

In 1969, ARPANET was started by U.S. Department of Defense to connect computers at U.S. defense & different universities. In 1980s, the National Science Foundation started NSFnet to make a high capacity network to be used strictly for academic and engineering research.

In 1990s, many private companies built their own networks, which were later interconnected along with ARPANET and NSFnet to form Internet. Later, the commercial Internet services came into picture, which are running the Internet.