Before we can load any data through the Facebook APIs, we will need to authenticate our application, and we'll need to do this each time our Flash movie is displayed in the HTML page (or each time our AIR application is launched).
The authentication process is fairly complex, based as it is on the OAuth 2.0 protocol, but it is thankfully wrapped up nicely and neatly by the Facebook ActionScript 3 SDK, so our actual setup in ActionScript isn't too complex.
This next image outlines the major layers involved when communicating with Facebook, through the Facebook ActionScript 3 SDK, from a Flash Platform application. It doesn't comprehensively outline every interaction or capability of the platforms, but it should give you an overview of the elements involved.
Facebook authentication is built around the OAuth 2.0 protocol, which in conceptual terms means that instead of having the user enter their login credentials to our third-party applications, they'll always be entering those credentials...