Many Terraform deployments begin with a single root module. As environments grow, teams need a reliable way to keep development, staging, and production isolated.
This lesson explores directory-based environments and the role of separate root modules. We examine how directories establish state boundaries, how environment-specific values are managed, and why backend separation matters.
The lesson also covers reusable child modules, environment ownership, deployment blast radius, and how CI pipelines can target only the directories that change.
Understanding these boundaries helps explain why many organizations use directory structures to manage infrastructure across multiple environments.