? marks in addresses

[MarkE]

Whatever business pages I visit, especially Microsoft and online stores, I always see question marks in the address bar that I think have to do with content-specific information. I usually see them in ASP and PHP files. How do question marks, ampersands, and semicolons work in web addresses, and how do I use them in my web pages?

[AdamBrill]

They are used to send variables across pages. Lets say you call a link like this: http://www.whatever.com/index.htm?100 Then, on index.htm, you put some script to take everything after the ?, which would return 100. It's just an easy way to send variables. :)