A parked domain is one which is taken, however it's not associated with another service - web or e-mail hosting. Put simply, this kind of domain will not load any real content if you type it inside an Internet browser, but nobody else can take it as you've already registered it and you are its owner. The advantage of acquiring a domain and parking it afterwards is that you can keep it and not worry that somebody else may register it meanwhile if, for instance, the site for it is not ready yet. You can set a temporary Under Construction page for a parked Internet domain while you're working on your web site, or forward it to another web address - temporarily or permanently. The second option can be used if you have already registered domain.com, for example, and you acquire domain.net and domain.org, in order to protect a brand name or a trademark. In cases like this, the .net and .org domain names can be parked and directed to the .com as you do not need different websites for them.