8.2. Collaboration and Governance
💡 First Principle: At team scale, "can it apply?" stops being just a technical question and becomes a policy question — so HCP Terraform inserts governance (policy-as-code) and collaboration controls into the run lifecycle, gating changes on organizational rules, not only on valid HCL.
Why care: Governance features — especially policy-as-code with Sentinel and OPA — are explicitly part of 004's expanded HCP coverage. The exam expects you to recognize what these features do and that they're platform capabilities, not core CLI features.
The mental model: Governance is the inspection step between the estimate and the construction. The plan can be technically valid yet still violate building codes (cost limits, tagging rules, allowed regions); policy checks are the inspector who can warn or block before work proceeds.
⚠️ Common Misconception: "Sentinel and OPA are part of open-source Terraform and are basically the same thing." Policy-as-code enforcement is an HCP Terraform / Enterprise governance feature, not part of the community CLI, and Sentinel and OPA are alternative policy engines (HashiCorp's Sentinel vs. the open-source Open Policy Agent), not one and the same.
