Four operations which lead to superimposition of an object on itself. These are rotation, Symmetry operation of shifting an object a given distance in a given direction. Translation may occur in 3 dimensions along axes that may or may not be perpendicular to one another. Crystal structures result from translation of a unit cell by the lengths of its edges along its crystallographic axes., reflection and inversion. The Property of an object if some spatial manipulation of it results in an indistinguishable object. A symmetric object can be superimposed on itself by some operation. of any object can be described by some combination of symmetry operations.