If you wish to register a domain name to make sure that nobody else will take it, however, you haven't developed the site for it yet, you could park it. That is a feature that registrar companies provide if a domain address is not connected to any web or e mail hosting service. This way, you can protect a brand name, for example, and you'll own the domain in question even though it will not load any content. If you wish, you can choose some default template that the registrar offers, like For Sale or Under Construction, or you can forward the domain to another web address. Your second option is very helpful in case you own a few domain names, but you want each and every one of them to open the same site. As an example, 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 name only and the traffic to the other ones will be redirected to it.