A node's a point along a standing wave where the wave has minimal amplitude. For instance, in a vibrating guitar string, the ends of the string are nodes. By changing the position of the end node through frets, the guitarist changes the effective length of the vibrating string and thereby the note played. The opposite of a node's an anti-node, a point where the amplitude of the standing wave's a maximum. These occur midway between the nodes. Explanation Standing waves result when two sinusoid… (More on Anti-node)