Registering a domain and hosting one is frequently mistaken by a lot of people to be the same thing. They're in reality 2 separate services - the domain registration is the actual name and nothing more, while the hosted domains feature reveals the amount of already registered domain names you can accommodate within the same website hosting account and have site data and e-mails for them. Your sites will work in exactly the same way regardless if 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 without hosting it will grant you ownership, but will not allow you to have a web site until you host this domain address in some account so that records for it are created and it starts opening the data from that account.