Amplitude described from "summary" of Vibrations and Waves in Physics by Iain G. Main

Amplitude is one of the most important measurements in physics since it describes various properties like wave frequency and energy. It is an oscillation in a wave or signal, measured as maximum displacement from its resting state.

In sound waves, amplitude determines the loudness of the sound, so high-amplitude sounds are louder than low-amplitude ones. Similarly, in light waves, higher amplitudes correspond to brighter lights.

The amplitude of any wave is determined by the area under its corresponding curve or graph; hence it is also referred to as the ‘strength’ of a wave.

An object's amplitude at a certain point in time indicates its overall range of motion; likewise, objects with smaller amplitudes move slower than those with larger amplitudes.

Wave amplitude affects how far a wave can travel in space: greater amplitude equals larger distances traveled. This means that louder sounds travel farther because of their larger amplitudes.

High-amplitude waves have more kinetic energy compared to low-amplitude waves, and their ability to do work is greater. For example, when we climb stairs with small amplitude vibrations we will not need much energy, but if these stairs were vibrating with a large amplitude it would require much more energy.

Any periodic signal has an amplitude associated with it to measure its size and magnitude. When graphed, this amplitude is shown as a peak atop the regular cycle of replications of a graph.

Periodic signals whose amplitudes vary significantly throughout their cycles are known as nonlinear periodic signals, while periodic signals with constant amplitudes (like a sine wave. are called linear periodic signals.