Facebook application iframe php

Please excuse me for being thick (or not) but doe开发者_如何学Pythons a FaceBook iframe (canvas) application "behave" like any other iframe on a website? - OK I'll accept you need access to the api etc with the keys, but once that is achieved am I being totally off the wall in thinking that a FB iframe application "just" runs the relevant app. pages in an iframe, exactly the same way that any other site does?

Basically, you are correct. Facebook does post some information through the iFrame to enable different parts of the JS library that you should load with the page to access their features. But in essance, they are loading an iFrame of a website and displaying it inside of their wrapper. Also it is very different than an FBML app because it is rendered on your server and then the rendered content is sent to the iFrame rather than the FBML being rendered by FB then displayed on the screen.