A parked domain address is one that is taken, but it is not connected to any other service - web or e mail hosting. Basically, this kind of domain name will not open any actual content in case you type it in a browser, but nobody else can take it as you've already registered it and you are its owner. The advantage of acquiring a domain name and parking it afterwards is that you will be able to keep it and not stress that someone else may register it meanwhile if, for instance, the site for it is not ready yet. You can set a temporary Under Construction webpage for a parked domain address while you're working on the 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 instance, and you acquire domain.net and domain.org, in order to protect a brand name or a trademark. In this situation, the .net and .org domain names can be parked and directed to the .com as you do not need separate sites for them.