Registering a domain and hosting one is usually mistaken by a lot of people to be the same thing. They are actually 2 separate services - the domain name registration is the actual name and nothing more, while the hosted domains feature shows the number of already registered domain addresses which you can accommodate within the same hosting account and have site files and emails for them. Your sites will work in exactly the same way regardless of whether the domain names are registered and hosted at the same place or are registered with company A and pointed to company B. Simply registering a domain name without hosting it will give you ownership, but will not allow you to have a web site unless you host this domain name in some account so that records for it are set up and it starts opening the information from that account.