There are two separate services that you’ll need for a working site - a domain and a hosting plan for it. If you type the domain address in your web browser, you see the content that’s uploaded within the website hosting account, but if that domain address is not linked to such an account or to an email service, it's parked. Put simply, the domain address is registered and you're its owner, but it doesn't have any content of its own. Instead, it can open either a pre-made “Under Construction / For Sale” webpage from the registrar company, or it could be forwarded to any other URL of your choice. The main advantage of parking a domain name is that you can keep it and make sure that nobody else is going to take it. In the meantime, it will not take a slot for a hosted domain name in your account. You may also park domains if you have a .com, for instance, and you register domains with other extensions such as .net, .org or country-code ones to direct them to the main website so as to protect a brand name.