The hosted domains feature of a web hosting account indicates the number of registered domain names that one can add in the very same account. Registering a domain and hosting it are 2 completely different services although many people consider them to be the same thing. While the registration ensures that you become the owner of a given domain address, the hosting element is what actually enables you to have a website as this is where your files and emails will be. As these are two independent services, you can register a new domain with one company and host it with another by changing its name servers (DNS) - the domain name is going to work in the exact same way just as if it was registered and hosted using the same company. Also, it is very important to know that changing the hosting means pointing the domain name to another company and not transferring it.