When I right click on your avatar, Paul (That’s the little picture of you beside the locomotive) I get a properties box. It’s full of information about that image, much of which is useful only to computer geeks. One of those lines contains the address of the image’s location on a server somewhere out there. That address is called the url. In the case of your avatar, this is its address, or url:
http://www.largescalecentral.com/public/user/0f/c8/01/1c548_0b88.JPG?c=abd0
Hope this helps.
Whoops, didn’t mean to step on your feet, Eric, I must’ve been typing when your post came through.