An addon domain is when you setup a 2nd domain of yours to point to a subdirectory off your main account so it will load a different site from the a subdirectory of your main domain. Types: Multi Domain - This is when you point your domain name to a subdomain/subdirectory on your account. This can be achieved by visiting your control panel and clicking addon domains. Domain Pointer - This is when you point your 2nd domain to your main domain.