If you'd like to register a domain name to make sure that no one else will take it, but you haven't built the website for it yet, you may park it. That is a service that registrar companies offer when a domain name isn't linked to any web or e-mail hosting service. In this way, you'll be able to protect a brand name, for instance, and you'll own the domain name in question although it will not open any content. If you'd like, you can select some default template that the registrar offers, such as For Sale or Under Construction, alternatively you can forward the domain name to a different web address. Your second option is very helpful in case you own a few domain names, but you want every one of them to open the same website. For example, you can register domain.net and domain.org, then park them and direct them to domain.com. In this example, you will need hosting for the third domain only and the traffic to the other ones will be redirected to it.