Warning: Do not edit the .htaccess file unless you are completely sure of what you are doing.
.htaccess is an Apache web server file that controls how files and folders are used within a specific directory or within an entire web site. Editing the .htaccess file can allow you to set up your own custom error pages or redirect a domain to another location (both of which can also be done by using other CPanel functions - refer to Error Pages and Redirects for more information.)
There are several instructions on how to use .htaccess for various functions in CPanel itself. You can also refer to http://www.javascriptkit.com/howto/htaccess.shtml for a comprehensive tutorial about .htaccess.
To edit the .htaccess file:
Click on the Edit .htaccess link in the Domain Menu area.
Edit the text in the main display area, as required.
Click on the Save button.