If you want to create a web site, you need 2 things - a domain and a hosting plan for it. The domain registration is the actual website address that you enter in a browser to access a website, while the hosting space is where your site files will be. These are two tightly connected, but independent services, even though many people assume that registering the domain name is enough. Just like the disk space and the monthly traffic features which a given web hosting plan has, there are a certain number of registered domain names that you can add as hosted i.e. you can have the web content for them in some account even when the domains have been registered using a different service provider. In technical terms, it doesn't matter whether a domain name is registered and hosted using the same company or is registered with one company and pointed to another one - in any case your sites will operate in exactly the same way.