If you've read even this far, then it's safe for me to assume that you're already well acquainted with Facebook, and (given the name of this book) it's also fairly safe to assume that you don't want an in-depth discussion on how to use Facebook—you just want to get on with building a Facebook application. So, that's exactly what we're going to do—we're going to build Pygoscelis P. Ellsworthy's Suspect Tracker as an example:

However, before we jump into building a Facebook application, we need to spend some time looking at the Facebook platform, and by the end of this chapter you will:

• Understand what the Facebook Platform is, and how it relates to your application
• Know about the elements that make up the Facebook Platform, and how to test them without having to create an application
• Know how to set up the Facebook Platform, ready for your new application

The Purpose of the Facebook Platform

As you develop your Facebook applications, you'll find that the Facebook Platform is essential—in fact you won't really be able to do anything without it. So what does it do? Well, before answering that, let's look at a typical web-based application.

The Standard Web Application Model

If you've ever designed and built a web application before, then you'd have done it in a fairly standard way. Your application and any associated data would have been placed on a web server, and then your application users will access it from their web browsers via the Internet:    

The Facebook model is slightly different.

Next Page: The Facebook Web Application Model