3.1. The Core Terraform Workflow
💡 First Principle: The Terraform workflow is a deliberate "look before you leap" cycle — you always see the planned changes before any are made — which is why the order write → plan → apply is a safety feature, not just a convention.
Why care: Most workflow questions test whether you understand the sequence and the boundaries between commands: what's read-only, what mutates infrastructure, what mutates only state. Internalizing the cycle prevents the most common exam mistakes.
The mental model: Treat the workflow like editing a document with track-changes. You write your edits (configuration), preview the marked-up diff (plan), and only then accept the changes (apply). Nothing is committed to the real document until you accept.
⚠️ Common Misconception: Beginners think plan and apply are basically the same command run in two steps. They're fundamentally different: plan is read-only and safe to run anytime; apply is the only step that changes real infrastructure. Treating plan as harmless and apply as the gate is the correct mental boundary.
