The Internet

Depiction of the Internet

Permissions
© Believed to be in the Public Domain

As noted in the Overview section, the Web can be viewed as a set of resources interconnected by embedded hyperlinks. However, the Web itself has no mechanism for actually making the hyperlinked connections. Instead, it relies on the Internet for the actual linking. So, to understand how the Web works, we need to understand at a high level how the Internet works.

A Very Brief and Slightly Irreverent History of the Internet

In the beginning of the age of computing there were computers. They were big. They were expensive. They were few. The were far between.

And they were hot!

Very hot, requiring separate high capacity air conditioning systems to keep them comfortable.

A Little Picture of a Big Computer: IBM 360, circa 1965
Your Smart Phone is More Powerful and Has Far More Memory Than This Behemoth

Permissions
©IBM Archives. Believed to be in the Public Domain

They were also lonely.

They were lonely because each was the only computer for miles around, and when their human masters were not using them they sat around twiddling their bits, having nothing to do.

Then as the number of computers began to grow some folks who were in charge of these warm, but not-so-cuddly beasts thought it might be worth a shot to hook them up. So, with Department of Defense funding they tried their ideas out on four computers in California. The relationship started on on the rocks. The first message sent between UCLA and Stanford crashed the computers before the sent message was completely transmitted. Apparently, the second one worked, and the romantic message login showed up on an output device at Stanford.

Descriptions of this event can be found by following these two links:,

This government-funded undertaking was successful and became known as ARPAnet, and then DARPAnet (ARPA stands for Advanced Research Projects Agency). DARPAnet made these somewhat rare and expensive scientific computers more widely available to researchers at universities and was the direct ancestor of the Internet.

Local Area Networks (LANs)

Once computers became more widely used in commerce, businesses sprang up that offered hardware and software to network an enterprise's computers together, and local area networks (LANs) were born. LANs by themselves only allow computers on the LAN to communicate with other computers on that LAN, not the outside world.