My friend and I have been working on some sites of ours and trying to get changes ready for the redesign, and she asked me why some sites have the "www" before them and others don't. And I couldn't answer. I feel kinda stupid now. I know that is stands for world wide web, but that's as much as I know.

What is the significance of the "www"?

thanks!

You can read about the history of it:
World Wide Web - Wikipedia, the free encyclopedia
(as you will find it out: it is a "subdomain" and The use of such subdomain names is not required by any technical or policy standard...)

Nowadays, most uses are for websites, so the www isn't a necessity and some people have just dropped it. Actually, it wasn't a necessity in the past either; it was more or less simply used for identification purposes.

For my newer sites (especially blogs), I've dropped the WWW altogether. Here's why...

(a) It's 4 extra characters on Twitter (www.) if you want to use your URL in a Twitter message.

(b) It's 4 extra characters on Google when they do their search summaries, and your post comes up like this...

http://copysnips.com/copywriting/men...s-better-copy/

... then more of the entire URL can be seen.

(c) I think one day, the "www." part will just disappear, so I'm just getting in there early. (For example, how many people type "http://" any more? That's where "www." will also go, one day.

I think it's just habit for some people to put it in there because almost everyone had to do it when the web first came out.