In order to create a web site, you need two things - a domain and a website hosting plan for it. The domain registration is the actual website address that you type in a browser to access a site, while the hosting space is where your website files will be. These are two tightly related, but independent services, while many people assume that registering the domain is enough. Similar to the disk space and the monthly traffic features that a given website hosting plan has, there are a certain number of registered domains which you can add as hosted which means that you can have the web content for them in some account even if the domains are in fact registered through a different firm. In technical terms, it doesn't matter whether a domain name is registered and hosted with the same company or is registered with one company and directed to a different one - in any case your sites will function the very same way.