The foundation for present day Internet, then known as Arpanet, was set up in 1969 by connecting four computers at different universities in southwestern US. Within a couple of years, the network grew considerably with MIT, Harvard, Carnegie-Mellon and even NASA, among various others, coming onboard.
The early Internet was primarily used by scientists, researchers, engineers and computer experts to share information. The whole system was very complex and anyone wishing to use it had to first learn to use it. It has gone through several changes since then and whole gamut of applications developed. It underwent major changes in the 70s when the TCP/IP architecture was proposed to replace the Network Control Protocol (NCP). The email, perhaps its most important application till date, was developed in the year 1972. Over time, the various commands were standardized, making it a lot easier for the people to use the Internet. This, along with the introduction of the Windows 98 operating system by Microsoft, really helped in propagating the benefits of Internet to millions of users around the world.