If you want to register a domain name to ensure that no one else will take it, but you haven't created the website for it yet, you could park it. This is a feature that registrar companies provide if a domain name is not connected to any web or email hosting service. That way, you can protect a brand name, for example, and you'll own the domain address in question even though it will not load any content. If you wish, you can pick some default template that the registrar offers, such as For Sale or Under Construction, or you can forward the domain to a different web address. Your second option is very helpful if you own a few domains, but you want each and every one of them to open the same site. As an illustration, you could register domain.net and domain.org, then park them and forward them to domain.com. In this example, you will need hosting for the third domain only and the traffic to the other ones is going to be redirected to it.