What phenomenon describes the peak height of a wave from its resting position?

The peak height of a wave from its resting position is defined as the amplitude of the wave. Amplitude is a measure of how far the wave's peaks (or crests) rise above the central resting position and also how far the troughs dip below that position. It quantifies the energy of the wave—the greater the amplitude, the more energy the wave carries.

In contrast, wavelength refers to the distance between two successive crests or troughs, which does not relate to the height of the wave. The crest specifically refers to the highest point of the wave itself, whereas amplitude encompasses the measurement from the resting position to the crest. Frequency indicates how often the wave oscillates in a given time period and does not pertain to the wave's height. Understanding the distinction between these terms is crucial in wave mechanics, as they each describe different characteristics of waves.