The hosted domains feature of a website hosting account refers to the number of registered domain names which you can add within the very same account. Registering a domain name and hosting it are two different services even though many people consider them to be the very same thing. While the registration ensures that you become the owner of a given domain name, the hosting aspect is what really enables you to have a website as this is where your files and email messages are going to be. Since these are 2 different services, you can register a new domain with one company and host it with another one by changing its name servers (DNS) - the domain name is going to work in the exact same way as if it was registered and hosted using the same company. Also, it is important to know that changing the hosting means pointing the domain name to an alternative company and not transferring it.