If you wish to register a domain name to make sure that nobody else will take it, however, you haven't built the site for it yet, you could park it. It's a feature that registrar companies offer whenever a domain name isn't connected to any web or e-mail hosting service. By doing this, you can protect a brand name, for example, and you'll own the domain name in question even though it won't open any content. If you'd like, you may choose some default template that the registrar offers, such as For Sale or Under Construction, or you can forward the domain to an alternative web address. Your second option is very helpful in case you own a few domain names, but you want every one of them to open the same site. As an 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 will be redirected to it.