When you have a number of domain names with different extensions and you need all of them to open the very same site, you may have the website under one of them and redirect the rest. There are a number of methods to forward one domain to another, such as the so-called domain parking. When your hosting package deal allows it, though, it shall be better if you host each of the domains and set up a URL redirect, not a domain redirect. The real 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. As an example, if you're building localized websites under several country-code domains, you shall be able to work on them, but at the same time, visitors shall be forwarded to the primary Internet site.