mod_rewrite is the Swiss army knife of URL manipulation. It enables you to perform any imaginable manipulation of URLs using powerful regular expressions. It provides rewrites, redirection, proxying, and so on. There is little that you cannot accomplish using this module.
If you have Apache installed and running, see http://localhost/manual/misc/rewriteguide.html for a cookbook that gives you an in-depth explanation of the
mod_rewrite module’s capabilities