Registering a domain and hosting one is commonly mistaken by many people to be one and the same thing. They're actually 2 separate services - the domain name registration is the actual name and nothing more, while the hosted domains feature refers to the number of already registered domains that one could accommodate in the same website hosting account and have site files and e-mails for them. Your sites will function in precisely the same way no matter if the domain addresses 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 enable you to have a web site if you don't host this domain in some account so that records for it are set up and it starts opening the content from that account.
