The motion shown when windmill wings (also known as blades or sails) are rotating is rotational motion.
Rotational motion involves the spinning or turning of an object around an axis. In the case of a windmill, the blades rotate around a central axis, converting the kinetic energy from the wind into mechanical energy, which can then be used to do work, such as grinding grain or generating electricity. This rotational motion is what allows windmills to harness wind energy for various purposes.