A parked domain name is one that is taken, but it's not linked to any other service - web or email hosting. Essentially, such a domain will not open any actual content in case you type it within a browser, but no one can take it as you've already registered it and you are its owner. The best thing about acquiring a domain name and parking it afterwards is that you are able to keep it and not worry that someone else could possibly register it in the meantime if, for instance, the website for it is not ready yet. You can create a short-term Under Construction page for a parked domain while you're working on the website, or direct it to another web address - temporarily or permanently. The latter option can be employed when you have already registered domain.com, for example, and you get domain.net and domain.org, so as to protect a brand name or a trademark. In such a case, the .net and .org domains can be parked and directed to the .com since you don't need different websites for them.