The Early Days Of The Internet
The earliest nodes that formed the internet were in the 1960s and were for the time-sharing of computer resources for the U.S. Department of Defense (DoD) and were part of the Advanced Research Projects Agency (ARPA). This gave birth to ARPANET which were interconnected networks between the Network Measurement Center at the University of California, Los Angeles (UCLA) and the NLS system at SRI International (SRI). ARPANET grew by interconnecting Universities and research centers and by 1971, there were 15 sites connected to form ARPANET.
The term internet was coined in 1974 by Vint Cerf and Bob Kahn as shorthand for internetwork in RFC 675, and the Internet was born.
ARPANET expanded into NSFNet which continued to grow internationally. By early 1990, bulletin board systems (BBS) like Compuserve had established connections to the internet, delivering email and access to half a million users.
This is where the World Wide Web (WWW) comes into play. The World Wide Web is a service offered on the Internet like email. The World Wide Web is a global collection of documents, images, multimedia, applications, and other resources, logically interrelated by hyperlinks and referenced with Uniform Resource Identifiers (URIs), which provide a global system of named references. (source).
Today we have several billion users on the internet and growing daily.