If you want to register a domain to make sure that nobody else will take it, however, you have not developed the website for it yet, you can park it. This is a feature that registrar companies provide whenever a domain is not connected to any web or email hosting service. That way, you are able to protect a brand name, for example, and you'll own the domain in question even though it won't open any content. If you wish, you can pick some standard template that the registrar provides, like For Sale or Under Construction, or you can direct the domain to an alternative web address. Your second option is very helpful if you own a number of domains, but you want each and every one of them to open the same site. For example, you may register domain.net and domain.org, then park them and forward 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.