Looking for your staged site? Contact Isaac for your link.
Staging is a phase in devlopment where a product (in this case, a website) is almost ready to be released into the world. The functionality here is almost exactly what it will be like for the user. The benefit of staging is that if anything goes wrong here, it won't affect customers on your forward facing site.
Unless you personally know everyone that will be using your site, yes. Production sites need to be stable so that users always have access. While stability is great, it can make it difficult to add new functionality. Staging lets you add that functionality without causing any disruptance to your main site. And, if anything does happen, you can fix it and fully integrate before anyone even knows something broke.
If I am creating a website for you, staging comes included. If you just want to host a pre-production version of your site, at this time that is not something I offer.
View the Wikipedia page for Staging.