There are 2 services that you need for a working web site - a domain and a website hosting plan for it. Whenever you type the domain in your Internet browser, you see the content that’s uploaded inside the website hosting account, but if that domain name isn't linked to such an account or to an email service, it is parked. To put it differently, the domain 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” webpage from the registrar company, or it may be forwarded to some other URL of your choice. The main advantage of parking a domain name is that you can keep it and ensure that nobody else is going to take it. In the meantime, it's not going to block a slot for a hosted domain within your account. You may also park domain names 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 as a way to protect a brand name.