The hosted domains feature of a web hosting account denotes the amount of registered domain names which you could add in the very same account. Registering a domain address and hosting it are 2 completely different services even though many people consider them to be the same thing. While the registration ensures that you become the owner of a given domain name, the hosting element is what in fact enables you to have a site considering that this is where your files and emails will be. Because these are two separate services, you can register a new domain with one company and host it with another by changing its name servers (DNS) - the domain address shall work in the exact same way just as if it was registered and hosted with the same company. It's also important to know that changing the hosting means pointing the domain name to an alternative company and not transferring it.