.htaccess files can be a little tricky, but when used by a skilled practitioner, they can do wonderfull things. Hone your skills by reading this Apache .htaccess tutorial.

“.htaccess (Hypertext Access) is the default name of Apache’s directory-level configuration file. It provides the ability to customize configuration directives defined in the main configuration file. The configuration directives need to be in .htaccess context and the user needs appropriate permissions.”