Registering a domain name and hosting one is usually mistaken by many people to be the same thing. They are in fact two separate services - the domain address registration is the actual name and nothing else, while the hosted domains feature reveals the amount of already registered domains which you could accommodate in the same hosting account and have website files and emails for them. Your sites will function in precisely the same way regardless if the domain names 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 grant you ownership, but will not enable you to have a web site unless you host this domain address in some account so that records for it are set up and it starts opening the information from that account.