There are two services that you need for a working site - a domain and a web hosting plan for it. Any time you type the domain in your browser, you see the content that’s uploaded within the website hosting account, but if that domain address isn't linked to such an account or to an e-mail service, it's parked. In other words, the domain name is registered and you're its owner, but it does not have any content of its own. Rather, it can open either a pre-made “Under Construction / For Sale” webpage from the registrar company, or it may be directed to some other URL of your choice. The main 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 won't occupy a slot for a hosted domain address in your account. In addition, you can 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 as a way to protect a brand name.