A wave vibrating at right angles to the direction of its propagation.

A vibration of a system in which some particular points remain fixed while others between them vibrate with the maximum amplitude.

A pulse wave or pulse train is a kind of non-sinusoidal waveform that includes square waves and similarly periodic but asymmetrical waves

In mathematics, a periodic travelling wave is a periodic function of one-dimensional space that moves with constant speed.

A wave vibrating in the direction of propagation.

Destructive interference occurs when the maxima of two waves are 180 degrees out of phase: a positive displacement of one wave is cancelled exactly by a negative displacement of the other wave.

Constructive interference occurs when the maxima of two waves add together (the two waves are in phase), so that the amplitude of the resulting wave is equal to the sum of the individual amplitudes.