Q. I thought all World Wide Web addresses had to have www in them, but I've seen some that don't. How can this be?

A. Let's break down the average Web address, known as a Uniform Resource Locator (U.R.L.) into bite-size parts. As an example, we'll use http://www.nytimes.com. You might assume that it is www that tells the computer that this is a Web site, but that is not the case.

The first part of the U.R.L. is what points you to the Web. That http:// stands for hypertext transfer protocol, which is the method Web-server computers use to connect to the Web. The last part of the U.R.L., nytimes.com, is the domain name.

The www is a common Internet standard indicating that the computer you're trying to reach is a Web server. But it's not mandatory, and it is not part of the domain name. Depending on how the system's administrators chose to set up their site, the www may be a required part of the U.R.L. (as in the case of www.nytimes.com). Some sites have opted to skip the www as part of their addresses (as in netsol.com) and some have set up electronic pointers that will direct those who type www.netsol.com to the right page. And some Web browsers, like the current versions of Netscape Navigator and Microsoft Internet Explorer, will helpfully insert the http://www. and the .com for you. If you use one of these, you can type nytimes in the address box and it will take you there. J. D. BIERSDORFER

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