What is an approval gate in a CD pipeline?

An approval gate (also called a manual gate or deployment gate) is a checkpoint in the CD pipeline that pauses automated progression and requires explicit human sign-off before continuing to the next stage. The most common use is requiring approval before deploying to production — the pipeline automatically deploys to staging, runs acceptance tests, and then pauses and notifies the team, waiting for an authorized person to review and approve the production deployment. GitHub Actions supports this via Environments with required reviewers. Jenkins implements it with the input step. Approval gates are essential in regulated industries (finance, healthcare) where a change advisory board (CAB) review is required before production changes, and in organizations that want human oversight before touching production despite having full test automation.