What does the word TREESAME mean in the context of git?

Question

I saw many references to TREESAME in the git log manual. But I did not know what it meant.

Answer 1

Given two or more trees, a pathspec is considered TREESAME if and only if there is no discernible difference for the pathspec among the respective trees.

More intuitively, one could think of TREESAME as meaning the same between trees.