Pointing an old resource at a new resource.
Ensuring changes to a system do not introduce new bugs in previously stable parts of a system.
Coordinating activities of a release in technology. Usually, a release is not as simple as bumping a code version, there may be lots of additional steps like database updates, redirect changes, certificate updates, etc. and all of those events are handled through automated release orchestration.
Reverting a running code version back to a previous state.