Registering a domain name and hosting one is sometimes mistaken by a lot of people to be one and the same thing. They're in fact 2 separate services - the domain address 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 within the same hosting account and have site files and emails for them. Your sites will work in precisely the same way regardless if the domain names are registered and hosted in one place or are registered with company A and directed to company B. Simply registering a domain without hosting it will give you ownership, but will not allow you to have a web site unless you host this domain in some account so that records for it are created and it starts opening the content from that account.