"Networks have become a fundamental, if not the most important, part of today's
information systems. They form the backbone for information sharing in
enterprises, governmental groups, and scientific groups. That information can
take several forms. It can be notes and documents, data to be processed by
another computer, files sent to colleagues, and multimedia data streams.
A number of networks were installed in the late 1960s and 1970s, when network
design was the “state of the art” topic of computer research and sophisticated
implementers. It resulted in multiple networking models such as packet-switching
technology, collision-detection local area networks, hierarchical networks, and
many other excellent communications technologies."
from "TCP/IP Tutorial and Technical Overview" located
here
