Isometry

An isometry, also called a congruence or a congruent transformation, is a distance-preserving transformation between two metric spaces, usually assumed to be bijective; the word comes from the ancient Greek isos, meaning equal, and metron, meaning measure. When the transformation maps a metric space to itself, it is a particular kind of geometric transformation known as a motion. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/