If you wish to register a domain to make certain that no one else will take it, however, you have not developed the website for it yet, you can park it. It's a service that registrar companies offer when a domain isn't connected to any web or e mail hosting service. By doing this, you can protect a brand name, for instance, and you'll own the domain name in question although it won't open any content. If you want, you can select some default template that the registrar offers, like For Sale or Under Construction, or you can forward the domain name to an alternative web address. The second option is very useful in case you own a number of domains, but you want every one of them to open the same website. For instance, you can register domain.net and domain.org, then park them and forward them to domain.com. In this example, you'll need hosting for the third domain name only and the traffic to the other ones will be redirected to it.