Simple Harmonic Motion (SHM) is a type of periodic motion where an object moves back and forth around a central position. This motion occurs when a restoring force, proportional to the displacement from the equilibrium position, acts on the object. Common examples of SHM include a swing, a pendulum, or a mass on a spring. In SHM, the object's position changes sinusoidally over time, meaning it follows a smooth, wave-like pattern. The key characteristics of SHM include its amplitude, which is the maximum distance from the equilibrium position, and its frequency, which is how often the motion repeats in a given time period.