Registering a domain name and hosting one is often mistaken by many people to be the same thing. They're in fact 2 different 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 you can accommodate in the same web hosting account and have site files and e-mails for them. Your sites will work in precisely the same way regardless if the domain addresses are registered and hosted at the same place or are registered with company A and directed to company B. Simply registering a domain address without hosting it will grant you ownership, but will not allow you to have a site if you don't host this domain in some account so that records for it are set up and it starts opening the information from that account.