CloudFormation Template Basics
Defining your resources in JSON.
An AWS CloudFormation template, which is a JSON document, may contain the following sections (keys):
Parameters Conditions Mappings Resources Outputs Note that only the Resources section is required to use a template, the rest are optional. In addition you can include:
AWSTemplateFormatVersion Description Metadata Parameters Parameters allow you to accept input into your CloudFormation stacks. It might be something as simple as the application name, it might be database parameters, it might be instance types for your EC2 instances.