When a wave is limited in its propagation at one or at both ends, a wave can appear with points which are not displaced with time (nodes); these are called stationary waves. These waves are produced by the superposition of identical waves travelling in opposite directions.
In the following visual you can vary the number of nodes and the amplitude of  two travelling waves which are superposed. If you carry out the proposed three activities you will have a better understanding of what these waves are like.

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