The hosted domains feature of a web hosting account refers to the amount of registered domain names that you can add within the same account. Registering a domain name and hosting it are 2 different services although some people consider them to be the very same thing. While the registration means you become the owner of a specific domain, the hosting aspect is what in fact permits you to have a site because this is where your data and e-mails 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 is going to work in the exact same way as if it was registered and hosted using the same company. It's also very important to know that changing the hosting means directing the domain to another company and not transferring it.