The hosted domains feature of a hosting account denotes the number of registered domain names which you can include within the same account. Registering a domain address and hosting it are two different services although a lot of people consider them to be the same thing. While the registration means you become the owner of a specific domain address, the hosting part is what actually allows you to have a website since this is where your files and e-mails will be. Since these are 2 separate services, you are able to register a new domain with one company and host it with another by changing its name servers (DNS) - the domain is going to work in the exact same way as if it was registered and hosted with the same company. It is also important to know that changing the hosting means directing the domain to another company and not transferring it.