If you wish to register a domain to ensure that no one else will take it, but you haven't built the 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 can protect a brand name, for example, and you will own the domain address in question although it will not open any content. If you'd like, you may choose some standard template that the registrar provides, like For Sale or Under Construction, alternatively you can forward the domain to a new web address. Your second option is very helpful if you own a number of domains, but you want every one of them to open the same site. For example, you may register domain.net and domain.org, then park them and direct them to domain.com. In this example, you are going to need hosting for the third domain name only and the traffic to the other ones is going to be redirected to it.