A parked Internet domain is one that is taken, however it's not linked to some other service - web or email hosting. To put it differently, such a domain won't load any real content in case you type it in an Internet browser, but nobody can take it as you've already registered it and you are its owner. The benefit of getting a domain name and parking it afterwards is that you will be able to keep it and not worry that somebody else could possibly register it meanwhile if, for example, 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 another web address - temporarily or permanently. The second option can be employed when you have already registered domain.com, for example, and you get 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 don't need separate websites for them.