Artefact promotionvsDeployment

Artefact promotion

the same version moves from staging to production by changing a reference, and no build runs to make that happen.

Advancing a specific artefact version through a sequence of environments as it earns confidence. It makes the question 'what is in production' answerable and gives rollback an obvious target — the version that was there before. Where promotion is implemented as a rebuild from a branch, none of those properties hold, which is the main practical reason branch-per-environment schemes go wrong.