Registering a domain name and hosting one is often mistaken by a lot of people to be the same thing. They are in fact two separate services - the domain registration is the actual name and nothing else, while the hosted domains feature refers to the number of already registered domain names that one could accommodate in the same website hosting account and have website files and e-mails for them. Your sites will work in precisely the same way no matter whether the domains are registered and hosted in one place or are registered with company A and directed to company B. Simply registering a domain name without hosting it will give you ownership, but will not allow you to have a website until you host this domain in some account so that records for it are set up and it starts opening the content from that account.