Bandwidth
The amount of data that can be transmitted at a given moment to a server. The higher your bandwidth the larger amount of traffic your site can handle at one time.

Billing Contact
When signing up with a web host or registering a domain name, the billing contact must be provided to the registrar/host when completing the registration form. The billing contact is responsible for receiving the bills and paying the registrar/host any fees.

Bulk Registration
When registering multiple domain names many registrars will offer bulk registration where you can register them all at once instead of individually.