In this lesson, the student will be introduced to cross-stack references as a way to share data between stacks. CloudFormation Templates are code (Infrastructure as Code), and it is good practice to modularize code. It can often be helpful to create multiple templates for an organization per functional group. But the need arises to share data between the stacks built from these templates and this can be done with Cross-Stack References. After getting a thorough introduction to Cross-Stack References, the student will be walked through the creation of stacks which use Cross-Stack References.