If you have a lot of domain names with different extensions and you need all of them to open the very same website, you can have the website under one of them and redirect the others. There are a number of methods to forward one domain to another, including the so-called domain parking. If your website hosting plan allows it, though, it'll be better if you host all of the domains and create a URL redirect, not a domain redirect. The primary difference between the two is that while a domain is hosted, you can still have content for it, create subdomains, e-mail addresses, and so forth., while with a parked domain it's not possible to do any of these things. For example, if you're building localized Internet sites under various country-code Internet domain names, you'll be able to work on them, but in the meantime, people shall be forwarded to the primary site.