What is a Virtual Domain ?
 

A Virtual Domain means having your own domain name without having to install expensive server hardware and software. A Virtual Domain is any domain name configured for a shared hosting account that is it's own website.

To add a virtual domain to your account, go to the Web Settings page of the hosting control panel and click the link Add A Virtual Domain.

when you combine a single server that support more than one domain,it's called virtual domain.this type of virtual hosting is often used by commercial enterprises that are seeking a low cost web site hosting option.