When engineers discuss Terraform environments, the conversation often starts with folders, workspaces, or Git branches.
The more important question is which resources share a state file.
A Terraform root module owns a state file, and that state file defines the operational boundary of an environment. Dev, staging, and production may reuse the same modules, but they should maintain separate state ownership.
In this lesson, I walk through common environment layouts, explain why separate roots create separate dependency graphs, and discuss why Git branches alone do not provide environment isolation.
Understanding state boundaries early helps prevent many of the environment management mistakes that appear later in larger Terraform deployments.