If you'd like to register a domain to ensure that no one else will take it, however, you haven't built the website for it yet, you may park it. That is a service that registrar companies offer if a domain name is not connected to any web or email hosting service. By doing this, you can protect a brand name, for example, and you will own the domain name in question even though it will not load any content. If you wish, you may choose some standard template that the registrar provides, like For Sale or Under Construction, you can also direct the domain to an alternative web address. Your second option is very useful if you own a number of domain names, but you want every one of them to open the same website. For example, you could register domain.net and domain.org, then park them and direct them to domain.com. In this example, you'll need hosting for the third domain only and the traffic to the other ones is going to be redirected to it.