What Does Google Apps for Your Domain Actually Do?

Dear Lifehacker,

I've been looking into Google Apps for Your Domain, which sounds cool, but I'm confused about what it is and why you'd use it. If I sign up for Google Apps for Your Domain, is Google actually becoming the host for my domain, or just providing a bunch of services for it? What's the advantage to using GAppsFYD versus just vanilla Gmail and the rest? I have my own domain name that I use for my primary email address and my web site.

Google Apps for Your Domain is pretty cool for folks with their own domain names who want to manage a bunch of email/calendar/homepage users for it. To answer your question, GAppsFYD does not become your domain host, but it does provide a bunch of services, like Gmail, Google Calendar, a Start Page (a la iGoogle), Google Docs, Google Talk, etc. The difference between GAppsFYD services and free vanilla Google services is what you'd expect: your domain.

For instance, if your domain is thesmithfamily.org, using GAppsFYD, you could set up a bunch of users who get Gmail, GCal, a personalized start page, and chat all with usernames like john@thesmithfamily.org, lisa@thesmithfamily.org. Your users would log in to a Google hosted control panel (which you can customize with a thesmithfamily.org logo), and all their email would get sent with their custom domain email as the From: address.