Board Thread:Site Discussions/@comment-26409147-20151010155157/@comment-1392727-20151014075753

I think that is the only difference, but it is a major one. A demotion requests what it suggests - the removal of a user's rights. The community decides whether the argument presented in the request is convincing enough for a demotion. A renewal is when the holder of those rights gives the community to re-vote if they should continue to keep their rights or not. A demotion presents an argument whereas the renewal does not.