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 the swinging of a pendulum and the vibration of a spring. In SHM, the object's speed is highest at the equilibrium position and slows down as it approaches the maximum displacement points, known as the amplitude. The motion is characterized by a constant frequency and a sinusoidal pattern, making it predictable and easy to analyze mathematically.