cPanel is an extremely powerful, web based control panel. What cPanel does is to provide a point and click interface to complicated system tasks, so even new users are able to control their hosting experience. cPanel allows you to manage almost every aspect of your hosting account.
With cPanel, you'll be able to add/remove email accounts, FTP, backups, files, CGI scripts, web-based statistics, and much more.
You can find more details about cPanel at http://www.cpanel.net/