Answer:
A standing wave is formed when the superposition of two travelling waves of the same frequency, polarization, and amplitude travelling in opposite directions.
Standing waves
A standing wave (stationary wave) is a wave that oscillates in time but does not alter its peak amplitude profile in space. The wave oscillations’ peak amplitude at any point in space is constant with time, and the oscillations at different points in the wave are in phase. Nodes are the locations where the absolute value of the amplitude is minimum, and antinodes are the locations where the absolute value of the amplitude is highest.