What is the term used for the maximum displacement of points on a wave from its rest position?

The term that refers to the maximum displacement of points on a wave from its rest position is wave amplitude. Amplitude is a critical characteristic of waves, representing how far the wave extends above and below its equilibrium or rest position. This measurement indicates the energy and intensity of the wave; higher amplitude generally correlates with a more intense wave.

In the context of sound waves, for instance, greater amplitude means louder sound, while in light waves, it can refer to the brightness of the light. Understanding amplitude is essential for analyzing various types of waves, including mechanical waves like sound, and electromagnetic waves like light.

Other terms related to wave characteristics, such as wavelength, wave period, and wave frequency, refer to different aspects of waves. Wavelength describes the distance between successive crest points, wave period refers to the time it takes for one complete cycle of the wave to pass a point, and wave frequency indicates how many cycles pass a point in a given time period. However, none of these terms define the concept of maximum displacement, which is specifically identified as amplitude.