There are 2 services you need for a working site - a domain name plus a web hosting plan for it. Each time you type the Internet domain in your web browser, you see the content that is uploaded inside the hosting account, but if that domain is not linked to such an account or to an email service, it is parked. In other words, the domain address is registered and you are its owner, but it doesn't have any content of its own. Instead, it can open either a pre-made “Under Construction / For Sale” page from the registrar company, or it could be forwarded to any other URL of your choice. The advantage of parking a domain name is that you can keep it and be sure that nobody else will take it. In the meantime, it will not occupy a slot for a hosted domain address within your account. You may also park domains if you have a .com, for instance, and you register domain names with other extensions such as .net, .org or country-code ones to direct them to the main site so as to protect a brand name.