If you want to register a domain to ensure that no one else is going to take it, but you haven't developed the web site for it yet, you could park it. This is a service that registrar companies offer whenever a domain name is not connected to any web or email hosting service. This way, you are able to protect a brand name, for instance, and you will own the domain name in question even though it won't open any content. If you wish, you can select 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 if you own a few domains, but you want all 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 address only and the traffic to the other ones will be redirected to it.