cPanel allows for adding additional domains to your existing account. The Addon domains are separate fully functional domains that are added from within the control panel. In short, cPanel is designed to allow multiple websites, all with a single control panel and hosting account. Most of the features of the primary domain, like creating e-mail accounts, forwarders, redirects etc. are available for addon domains as well. All this, managed with a single cPanel account.
Addon domains work by converting a sub-domain of your primary account and giving it a separate domain name, totally independent of the primary domain name.
Let us see how this can be done easily, from within the cPanel account :