Registering a domain and hosting one is commonly mistaken by a lot of people to be one and the same thing. They're in fact two separate services - the domain address registration is the actual name and nothing else, while the hosted domains feature shows the amount of already registered domain names you can accommodate within the same website hosting account and have site files and e-mails for them. Your sites will work in precisely the same way regardless of whether the domain addresses are registered and hosted in one place or are registered with company A and pointed to company B. Simply registering a domain address without hosting it will grant you ownership, but will not enable you to have a web site if you don't host this domain name in some account so that records for it are created and it starts opening the content from that account.
Hosted Domains in Shared Website Hosting
When you use shared website hosting you'll be able to host a different number of domain addresses, regardless of whether you register them with our company or through some other company. If you host only a few domains, you'll probably use a smaller amount of resources, so you can go for a lower-end plan, which will be less expensive. If you want to add more domains to your account later on, you can add additional slots using your hosting Control Panel and keep the current plan or upgrade your entire plan and use the extra system resources for the new domains. Each of the upgrades requires just a couple of mouse clicks and is activated instantly. Since registering and hosting a domain address are two different things, there is no limit on the number of domain addresses you can register whatever the plan you’ve subscribed for.