You can "park" or point another domain on top of your existing domain. This is also called "Domain Alias", which basically means, if you have
You can have www.parkeddomain.com or www.aliasdomain.com to point to the same website as the above.
Furthermore, you can also have all emails sent to firstname.lastname@example.org to go to the corresponding mail account on domain.com. This feature is called "Mail Domain Alias" which is complements the Domain Alias feature.
You may add as many number of parked domains as you wish. The parked domains do not count towards the domains limit of your account.