Registering a domain name and hosting one is usually mistaken by many 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 refers to the number of already registered domain names that one could accommodate within the same web hosting account and have site data and e-mails for them. Your sites will function in precisely 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 address without hosting it will grant you ownership, but will not allow you to have a website unless you host this domain in some account so that records for it are created and it starts opening the information from that account.