In case you have a lot of domains with different extensions and you would like all of them to open the same website, you may have the site under one of them and redirect the rest. There are various ways to redirect one domain name to another, among them the so-called domain parking. If your web hosting plan allows it, though, it shall be better if you host each of the domains and create 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 you are unable to do any of those things. As an example, if you're building localized websites under different country-code Internet domain names, you'll be able to work on them, but at the same time, people shall be forwarded to the main website.
