1.5: What Web addresses mean

When the Internet was in its infancy, it consisted of a small number of computers hooked together with modems and telephone lines. The only way to connect with another computer was to provide the IP address of that computer. A typical IP address might be

As more and more systems came online, the number system became unwieldy. The problem was compounded by the necessity to extend Internet access to those lacking knowledge of the computer’s inner workings.

The first solution to the problem was a simple text file maintained by the Network Information Center that mapped names to IP addresses. Soon this text file became so large, it was too cumbersome to manage.

In 1983, the University of Wisconsin created the Domain Name System. It maps text names to IP addresses automatically. The user needs to remember only www.stthomas.edu, for example, instead of St. Thomas’ IP address.


The URL system

When you use the Web or send an e-mail message, you use a domain name to do it. For example, look at the Uniform Resource Locator (URL) in the image above.

It contains: