Stationary waves are waves that do not transfer energy. These occur where both ends of the wave are in fixed positions. An example of this would be a string on a violin. As the wave reachs the end of the string it is reflected back onto the oncoming wave. This is called a superposition. Certain parts of the wave are seen to have no disturbance at all. These are called Nodes and occur where one wave's displacement is canceled out by the other wave and there in no net displacement. This is called destructive interference. Other parts of the wave have parts of maximum disturbance where the peak of one wave meets the peak of the other wave. This is called the antinode. the relative amplitudes and number of nodes and antinodes varies the sound which is heard by the violin