There are two separate services you'll need for a functioning web site - a domain name plus a website hosting plan for it. Any time you type the domain name in your browser, you see the content that’s uploaded inside the hosting account, but if that domain is not linked to such an account or to an e-mail service, it is parked. Put simply, the domain is registered and you are its owner, but it lacks content of its own. Rather, it can open either a pre-made “Under Construction / For Sale” page from the registrar company, or it could be directed to any other URL of your choice. The main benefit of parking a domain name is that you can keep it and make sure that nobody else will take it. In the meantime, it's not going to occupy a slot for a hosted domain address within your account. You could also park domains if you have a .com, for example, and you register domain names with other extensions such as .net, .org or country-code ones to forward them to the main web site so as to protect a brand name.