Registering a domain and hosting one is usually mistaken by many people to be the same thing. These are actually 2 separate services - the domain name registration is the actual name and nothing else, while the hosted domains feature shows the amount of already registered domain addresses that you can accommodate in the same web hosting account and have website data and emails for them. Your websites will work in precisely the same way no matter if the domains are registered and hosted in one 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 enable 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 content from that account.