Registering a domain name and hosting one is commonly mistaken by many people to be one and the same thing. They are in reality two different services - the domain registration is the actual name and nothing more, while the hosted domains feature reveals the number of already registered domain names which you can accommodate in the same hosting account and have website files and email messages for them. Your sites will work in exactly the same way no matter if the domain names are registered and hosted at the same place or are registered with company A and pointed 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 created and it starts opening the content from that account.