The hosted domains feature of a website hosting account refers to the number of registered domain names that one can include in the same account. Registering a domain and hosting it are two completely different services although many people consider them to be the same thing. While the registration signifies that you become the owner of a given domain name, the hosting element is what in fact allows you to have a website because this is where your data and emails are going to be. Since these are two independent services, you can 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 as if it was registered and hosted using the same company. It is also extremely important to know that changing the hosting means directing the domain to a different company and not transferring it.