A web hosting package starts with one domain called main domain. The purpose of an alias domain is to display the same content and to function in the same way as the main domain. An alias domain points to the same folder as the main domain. You can create e-mail addresses in the same way as with your main domain.

Example:
You order a web hosting package with the domain yourdomain.com. You want yourdomain.net to display the same web pages and order yourdomain.net as an alias domain. Yourdomain.com and yourdomain.net will then display the same web pages and you will be able to create e-mail addresses on both domains (e.g. name@yourdomain.com and name@yourdomain.net).