Objects which are identical except for a mirror reflection are said to display handedness and to be chiral.
Handedness
See also
Amphichiral, Chiral, Enantiomer, Mirror ImageExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Handedness." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Handedness.html