The hosted domains feature of a website hosting account indicates the amount of registered domain names that one could add in the same account. Registering a domain and hosting it are two different services even though many people consider them to be the same thing. While the registration means that you become the owner of a given domain name, the hosting aspect is what actually allows you to have a website as this is where your data and e-mails will be. Because these are two separate services, you can register a new domain name with one company and host it with another one by modifying its name servers (DNS) - the domain shall 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 name to a different company and not transferring it.