A parked domain name is one which is taken, but it's not linked to another service - web or email hosting. Basically, this kind of domain address will not load any actual content if you type it within a web browser, but no one else can take it as you've already registered it and you are its owner. The advantage of getting a domain name and parking it afterwards is that you can keep it and not worry that somebody else might register it in the meantime if, for example, the website for it is not ready yet. You could set a short-term Under Construction page for a parked domain name while you're working on your site, or forward it to another web address - temporarily or permanently. The latter option can be used if 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 cases like this, the .net and .org domain addresses can be parked and directed to the .com since you don't need different sites for them.