In classical physics, EM waves propagate this is one of the main features of all waves in general. Usually for mechanical waves the elements (like molecules) that vibrate do some little motion. For example a string can move up and down, but the waves travel further through propagation. The information or a signal carried by these waves travels by propagation. For EM waves there is not even vibration (mechanical) of the elements involved but only a variation of E and B fields. For these waves there seem to be absolutely no physical motion involved. What about the quantum mechanical photons? Is there any physical motion involved? Because if photons propagate and not move then I suppose it is likely that all particles do that. Does the motion we know from classical physics where an object keeps its identity exist in QM or QFT?