Simple harmonic motion (SHM) describes the motion of an object undergoing displacement from an equilibrium position due to a restoring force proportional to the displacement. The motion is periodic and sinusoidal, with the displacement following the equation x=A sin(ωt+φ), where A is the amplitude, ω is the angular frequency, t is time, and φ is the phase. Examples of SHM include a mass attached to a spring and the pendular motion of a mass hanging from a fixed point by a string.