A standing wave also called a stationary wave is a wave that is still during a constant position. It can arise during a stationary medium as a result of interference between two waves of equal wavelengths, travelling along an equivalent path but in opposite directions. they ought to have almost the same amplitude. Stationary waves are characterized by the confinement of a wave disturbance between two rigid boundaries. This means, the wave does not move forward or backward in a medium (does not advance), it remains steady at its place. Therefore, they are called "stationary waves or standing waves". Certain points in the region in which the wave exists have maximum amplitude, called as anti-nodes and at certain points the amplitude is minimum or zero, called as nodes.