The hosted domains feature of a website hosting account refers to the number of registered domains which you can add in the very same account. Registering a domain address and hosting it are two completely different services although some people consider them to be the exact same thing. While the registration means you become the owner of a specific domain address, the hosting part is what really allows you to have a website since this is where your files and emails are going to be. Because these are two independent services, you'll be able to register a new domain address 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 exact same company. Additionally, it is very important to know that changing the hosting means directing the domain name to a different company and not transferring it.