A parked domain is one that's taken, but it is not associated with some other service - web or e-mail hosting. Put simply, such a domain address won't open any real content when you type it within a web browser, but no one else can take it as you have already registered it and you are its owner. The advantage of acquiring a domain name and parking it afterwards is the fact that you are able to keep it and not stress that someone else could possibly register it in the meantime if, for example, the website for it is not ready yet. You can create a short-term Under Construction page for a parked domain address while you are working on your site, or forward it to another web address - temporarily or permanently. The latter option can be employed if you have already registered domain.com, for example, and you acquire domain.net and domain.org, so that you can protect a brand name or a trademark. In this situation, the .net and .org domains can be parked and directed to the .com as you do not need different websites for them.