Devshed style url's

Hi,
I think most of you know devshed.com.
In this site there are many articles stored on mysql database. And the site is based on php.

It isn't something like article.php?category=php&articleid=233 ...

I think the directorys Server_Side or Administration doesn't really exist on apache...

I know that there's a module named mod_rewrite in apache.. and with this you can do the same thing...

I don't know how to do this... If any one knows a tutorial about this subject or knows how to to it, please reply to my message..

Thanks a lot.