A parked domain address is one that's taken, yet it is not connected to another service - web or e-mail hosting. Basically, this kind of domain name will not open any actual content if you type it in a web browser, but no one can take it as you've already registered it and you are its owner. The main advantage of acquiring a domain and parking it afterwards is that you will be able to keep it and not worry that somebody else might register it in the meantime if, for example, the site for it is not ready yet. You are able to create a temporary Under Construction website page for a parked domain name while you're working on your site, or forward it to some other web address - temporarily or permanently. The latter option can be used when you have already registered domain.com, for example, and you acquire domain.net and domain.org, so as to protect a brand name or a trademark. In such a case, the .net and .org domains can be parked and forwarded to the .com since you don't need separate sites for them.