The hosted domains feature of a website hosting account denotes the amount of registered domains that one could include in the very same account. Registering a domain and hosting it are two totally 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 allows you to have a site since this is where your files and emails are going to be. As these are 2 different services, you'll be able to register a new domain with one company and host it with another by changing its name servers (DNS) - the domain name will work in the exact same way just as if it was registered and hosted using the same company. Also, it is important to know that changing the hosting means directing the domain to another company and not transferring it.