Preface (2 of 3) -- FIRST LINKS

     In the 1960s, researchers began experimenting with linking computers
to each other and to people through telephone hook-ups, using funds from
the U.S Defense Department's Advanced Research Projects Agency (ARPA).
     ARPA wanted to see if computers in different locations could be
linked using a new technology known as packet switching, which had the
promise of letting several users share just one communications line.
Previous computer networking efforts had required a line between each
computer on the network, sort of like a train track on which only one
train can travel at a time.  The packet system allowed for creation of a
data highway, in which large numbers of vehicles could essentially share
the same lane.  Each packet was given the computer equivalent of a map
and a time stamp, so that it could be sent to the right destination,
where it would then be reassembled into a message the computer or a human
could use.
     This system allowed computers to share data and the researchers to
exchange electronic mail, or e-mail.  In itself, e-mail was something of
a revolution, offering the ability to send detailed letters at the speed
of a phone call.
      As this system, known as ARPANet, grew, some enterprising college
students (and one in high school) developed a way to use it to conduct
online conferences.  These started as science-oriented discussions, but
they soon branched out into virtually every other field, as people
realized the power of being able to "talk" to hundreds, or even
thousands, of people around the country.
     In the 1970s, ARPA helped support the development of rules, or
protocols, for transferring data between different types of computer
networks.  These "internet" (from "internetworking") protocols made it
possible to develop the worldwide Net we have today.
     By the close of the 1970s, links developed between ARPANet and
counterparts in other countries.  The world was now tied together in a
computer web.
     In the 1980s, this network of networks, which became known
collectively as the Internet, expanded at a phenomenal rate.  Hundreds,
then thousands, of colleges, research companies and government agencies
began to connect their computers to this worldwide Net.  Some
enterprising hobbyists and companies unwilling to pay the high costs of
Internet access (or unable to meet stringent government regulations for
access) learned how to link their own systems to the Internet, even if
"only" for e-mail and conferences.  Some of these systems began offering
access to the public. Now anybody with a computer and modem -- and
persistence -- could tap into the world.
     In the 1990s, the Net grows at exponential rates.  Some estimates
are that the volume of messages transferred through the Net grows 20
percent a month.  In response, government and other users have tried in
recent years to expand the Net itself.  Once, the main Net  backbone  in
the U.S. moved data at 1.5 million bits per second.  That proved too slow
for the ever increasing amounts of data being sent over it, and in recent
years the maximum speed was increased to 45 million bits per second. Even
before the Net was able to reach that speed, however, Net experts were
already figuring out ways to pump data at speeds of up to 2 billion bits
per second -- fast enough to send the entire Encyclopedia Britannica
across the country in just one or two seconds.