There are 2 services that you’ll need for a working web site - a domain plus a hosting plan for it. When you type the domain name in your browser, you see the content that’s uploaded in the website hosting account, but if that domain name isn't linked to such an account or to an email service, it is parked. In other words, the domain address 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 can be directed to some other URL of your choice. The main benefit of parking a domain is that you can keep it and make certain that no one else will take it. In the meantime, it's not going to block a slot for a hosted domain name inside your account. You can 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 website in order to protect a brand name.