If you have several domains with different extensions and you want all of them to open precisely the same website, you can have the Internet site under one of them and forward all the rest. There are several approaches to forward one domain name to another, like the so-called domain parking. When your website hosting package permits it, though, it'll be better if you host all the domains and set up a URL redirect, not a domain redirect. The main difference between the two is that while a domain name is hosted, you may still have content for it, create subdomains, e-mail addresses, and so on., while with a parked domain it's not possible to do any of those things. For instance, if you are building localized Internet sites under various country-code Internet domain names, you'll be able to work on them, but in the meantime, people will be redirected to the primary site.