The hosted domains feature of a hosting account denotes the amount of registered domain names that you could include in the exact same account. Registering a domain name and hosting it are two different services even though many people consider them to be the same thing. While the registration means you become the owner of a certain domain name, the hosting part is what actually enables you to have a website as this is where your files and e-mails will be. Since these are 2 different services, you are able to register a new domain address 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 just as if it was registered and hosted with the exact same company. It is also extremely important to know that changing the hosting means pointing the domain to an alternative company and not transferring it.