If you want to register a domain name to make sure that nobody else is going to take it, however, you haven't built the web site for it yet, you could park it. It's a service that registrar companies provide if a domain name isn't connected to any web or e-mail hosting service. In this way, you are able to protect a brand name, for instance, and you will own the domain name in question even though it won't open any content. If you wish, you can choose some default template that the registrar offers, like For Sale or Under Construction, alternatively you can forward the domain name to another web address. The second option is very useful in case you own a few domains, but you want each and every one of them to open the same website. For example, you may register domain.net and domain.org, then park them and forward them to domain.com. In this example, you're going to need hosting for the third domain only and the traffic to the other ones is going to be redirected to it.