Cpanel Addon Domains
Domains helps you manage subdomains, addon domains and redirects. Although there are more features, addon domains and redirects are popular selections.
The addon domain button allows you to create an addon domain for the account. For example, if you have a main account with the domain example.com, you can reside the domain example2.com here as well. For shared hosting, it can be a pretty good bang for the buck.
Redirects allow you to redirect domains to other web addresses. For example, you may want all traffic that goes to example.com to redirect to example2.com.
To create an addon domain,
1) Select 'Addon Domains'.
2) Type in domain name, username and password.
3) Select 'Add Domain'.