What’s the difference between git reset –hard and git reset –merge

From git reset manpage:

--hard    Matches the working tree and index to that of the tree being
               switched  to. Any changes to tracked files in the working tree since
               <commit> are lost.

--merge
              Resets the index to match the tree recorded by the named commit, and
              updates the files that are different between the named commit and
              the current commit in the working tree.

The git reset --merge is meant to be a safer version of git reset --hard, when your changes and somebody else changes are mixed together, trying to carry our changes around.