Registering a domain and hosting one is commonly mistaken by many people to be the same thing. They are actually 2 different services - the domain address registration is the actual name and nothing more, while the hosted domains feature reveals the number of already registered domain names that you can accommodate within the same hosting account and have website files and e-mails for them. Your sites will work in exactly the same way no matter if the domain addresses are registered and hosted at the same place or are registered with company A and directed to company B. Simply registering a domain name without hosting it will grant you ownership, but will not allow you to have a website 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.