A parked Internet domain is one that is taken, however it's not associated with any other service - web or email hosting. To put it differently, such a domain name will not open any actual content when you type it inside an Internet browser, but nobody can take it as you have already registered it and you are its owner. The best thing about getting a domain name and parking it afterwards is the fact that you are able to keep it and not worry that someone else might register it meanwhile if, for example, the website for it is not ready yet. You may set a temporary Under Construction page for a parked domain while you're working on the web site, or direct it to some other web address - temporarily or permanently. The second option can be used when you have already registered domain.com, for example, and you obtain domain.net and domain.org, in order to protect a brand name or a trademark. In such a case, the .net and .org domains can be parked and forwarded to the .com since you do not need separate websites for them.