Addon domains are handled similarly to subdomains in terms of the file structure listed in your file directory; however, the addon domain URL appears like a primary domain. In general, nothing that happens in your addon domain’s files or DNS should affect what goes on with the rest of your domains.
Although addon domains do not have their own cPanel, you may still create email accounts, redirects, QuickInstall installations, subdomains, etc. Web statistics for the addon domain can be found under the subdomain’s URL in the statistics application in cPanel.
Addon Domain URLs
Every addon domain is also a subdomain. You may actually load your addon domain using any of the following URLs:
Addon Domain Name
http://addondomain.com/
Subdomain Name
http://addondomain.primarydomain.com/
Subfolder Name
http://primarydomain.com/addondomain.com/