motion,
movement the act of changing location from one place to another; "police controlled the motion of the crowd"; "the movement of people from the farms to the cities"; "his move put him directly in my path"
jitter -
small rapid variations in a waveform resulting from fluctuations in the voltage supply or mechanical vibrations or other sources
Jitter in technical terms is the deviation in or displacement of some aspect of the pulses in a high-frequency digital signal. As the name suggests, jitter can be thought of as shaky pulses. The deviation can be in terms of amplitude, phase timing, or the width of the signal pulse.
