The hosted domains feature of a website hosting account refers to the number of registered domain names that you can add in the very same account. Registering a domain and hosting it are two totally different services although many people consider them to be the very same thing. While the registration means that you become the owner of a given domain address, the hosting part is what in fact permits you to have a website considering that this is where your data and emails will be. Because these are 2 independent services, you are able to register a new domain address with one company and host it with another one by modifying its name servers (DNS) - the domain name shall work in the exact same way just as if it was registered and hosted with the exact same company. It's also extremely important to know that changing the hosting means pointing the domain name to an alternative company and not transferring it.