A parked domain is one that is taken, but it is not associated with any other service - web or email hosting. To put it differently, such a domain name will not load any actual content when you type it inside a browser, but nobody can take it as you've already registered it and you are its owner. The best thing about obtaining a domain name and parking it afterwards is that you’ll be able to keep it and not stress that someone else could possibly register it in the meantime if, for example, the site for it is not ready yet. You are able to create a temporary Under Construction page for a parked domain while you are working on the website, or direct it to another web address - temporarily or permanently. The second option can be used if 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 cases like this, the .net and .org domains can be parked and directed to the .com because you do not need individual websites for them.