Registering a domain and hosting one is commonly mistaken by many people to be one and the same thing. These are actually 2 separate services - the domain name registration is the actual name and nothing more, while the hosted domains feature refers to the amount of already registered domains which you can accommodate in the same hosting account and have website files and email messages 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 pointed to company B. Simply registering a domain name without hosting it will give you ownership, but will not allow you to have a web site until you host this domain address in some account so that records for it are set up and it starts opening the content from that account.