Registering a domain and hosting one is usually mistaken by a lot of people to be the same thing. They're in reality two separate services - the domain address registration is the actual name and nothing else, while the hosted domains feature shows the number of already registered domain addresses that one could accommodate within the same hosting account and have site files and emails for them. Your sites will function in precisely the same way no matter whether the domain addresses are registered and hosted at the same place or are registered with company A and pointed to company B. Simply registering a domain address without hosting it will give you ownership, but will not allow you to have a web site if you don't host this domain name in some account so that records for it are created and it starts opening the information from that account.