Registering a domain name and hosting one is commonly mistaken by a lot of people to be one and the same thing. They are in fact two different services - the domain registration is the actual name and nothing more, while the hosted domains feature shows the number of already registered domain names which you could accommodate in the same hosting account and have site files and emails for them. Your sites will work in precisely the same way regardless of 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 address without hosting it will grant you ownership, but will not enable you to have a site until you host this domain address in some account so that records for it are created and it starts opening the content from that account.