A parked domain address is one that's taken, but it's not connected to another service - web or email hosting. To put it differently, this kind of domain address won't open any actual content in case 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 main advantage of acquiring a domain name and parking it afterwards is that you’ll be able to keep it and not stress that someone else may register it meanwhile if, for instance, the website for it is not ready yet. You could set a temporary Under Construction website page for a parked domain while you are working on the web 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 instance, and you acquire domain.net and domain.org, so as to protect a brand name or a trademark. In this situation, the .net and .org domain addresses can be parked and forwarded to the .com because you don't need different websites for them.