If you want to register a domain to make sure that no one else will take it, but you have not created the web site for it yet, you may park it. This is a feature that registrar companies offer whenever a domain name isn't linked to any web or e-mail hosting service. In this way, you'll be able to protect a brand name, for example, and you will own the domain address in question although it will not open any content. If you want, you may choose some standard template that the registrar provides, like For Sale or Under Construction, or you can direct the domain to a new web address. The second option is very useful in case you own a few domains, but you want every one of them to open the same site. For instance, you could register domain.net and domain.org, then park them and direct them to domain.com. In this example, you're going to need hosting for the third domain address only and the traffic to the other ones will be redirected to it.