If you want to register a domain to ensure that nobody else is going to take it, however, you have not created the site 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 will own the domain name in question although it won't open any content. If you'd like, you can choose some default template that the registrar offers, like For Sale or Under Construction, you can also direct the domain name to a new web address. Your second option is very helpful in case you own a few domains, but you want every one of them to open the same site. For instance, you may 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 address only and the traffic to the other ones is going to be redirected to it.