I've seen some posts about merged questions on Meta Stack Overflow. What are merged questions, who can merge questions and what is the policy around this? What happens to reputation on questions and answers for merged questions? Is this similar to closing? Can users vote to merge and unmerge or is this only done by diamond moderators?
Questions can be merged by diamond moderators when one question is an exact duplicate of the other.
Users cannot vote to merge questions, but they can flag for a moderator to do so (this should only be done in cases where the answers to the new question make sense as answers to the original, so they really need to be close to exact duplicates).
Canonical or master question