Registering a domain and hosting one is commonly mistaken by a lot of people to be one and the same thing. They're in reality 2 different services - the domain address registration is the actual name and nothing else, while the hosted domains feature reveals the amount of already registered domain names that you can accommodate within the same hosting account and have site files and email messages for them. Your websites will work in precisely the same way regardless if the domain addresses 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 enable you to have a site until you host this domain address in some account so that records for it are created and it starts opening the information from that account.