Registering a domain and hosting one is sometimes mistaken by many people to be 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 refers to the amount of already registered domains which you could accommodate in the same website hosting account and have site files and emails for them. Your websites will work in precisely the same way regardless of whether 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 give you ownership, but will not enable you to have a site until you host this domain name in some account so that records for it are set up and it starts opening the content from that account.