There are two services that you need for a working web site - a domain name and a website hosting plan for it. Any time you type the domain address in your Internet browser, you see the content that’s uploaded in the hosting account, but if that domain name isn't linked to such an account or to an e-mail service, it is parked. In other words, the domain address is registered and you're its owner, but it doesn't have any content of its own. Rather, it can open either a pre-made “Under Construction / For Sale” page from the registrar company, or it may be directed to some other URL of your choice. The benefit of parking a domain address is that you can keep it and make sure that no one else will take it. In the meantime, it's not going to block a slot for a hosted domain address in your account. You could 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 in order to protect a brand name.