How was a URL like http://stackoverflow.com/posts/1807421/edit created in PHP?

Question

When you edit a question on stackoverflow.com, you will be redirected to a URL like this:

https://stackoverflow.com/posts/1807421/edit

Answer 1

I am poor at this but i do know you can redirect urls using apache mod_rewrite and by touching config files. From what i remember htaccess can be used to redirect. Then internally when the user hits http://stackoverflow.com/posts/1807421/edit it can use your page http://stackoverflow.com/edit.php?p=1807421 instead or whatever you want.