I'm seeing it on a lot of sites lately and I was wondering what it does and is it a lot of work? Also if you could, please post a link that could help me. thanks :)

http://www.google.com/search?hl=en&ie=UTF-8&q=define%3A+PHP

it is a serverside language.
imagine HTML coding on a power trip times 10.
it lets you do all sorts of stuff like guestbooks, form processing, forums and so forth.
if you have a database like MySQL, then using PHP becomes an even more powerful tool.

you can do a search for tutorials or check out peoples sites through here as there are usually many links around.

you can find more about php on http://php.net and what pb&j said is true. Its like a addon to html, makes it much more powerfull.

cool. thanx everyone! :)