The CloudFormation service allows you to provision and manage a collection of AWS resources in an automated and repeatable fashion. In AWS terminology, these collections are referred to as stacks. Note however that a stack can be as large or as small as you like. It might consist of a single S3 bucket, or it might contain everything needed to host your three-tier web app.

In this chapter, we'll show you how to define the resources to be included in your CloudFormation stack. We'll talk a bit more about the composition of these stacks and why and when it's preferable to divvy up resources between a number of stacks. Finally, we'll share a few of the tips and tricks we've learned over years of building countless CloudFormation stacks.