The hosted domains feature of a hosting account refers to the number of registered domains which you could add within the same account. Registering a domain address and hosting it are 2 totally different services although many people consider them to be the very same thing. While the registration means that you become the owner of a given domain name, the hosting aspect is what in fact enables you to have a website as this is where your data and emails will be. Since these are two independent services, it is possible to register a new domain name with one company and host it with another by changing its name servers (DNS) - the domain is going to work in the exact same way just as if it was registered and hosted with the exact same company. Also, it is extremely important to know that changing the hosting means pointing the domain address to another company and not transferring it.