This presentation introduces simple harmonic motion (SHM) and its applications. SHM describes a back-and-forth motion where the restoring force is directly proportional to displacement from the equilibrium position. One example is the motion of a spring according to Hooke's law, where the force is proportional to displacement. SHM has a differential equation and solutions that describe oscillations with a characteristic frequency and period. Common applications that exhibit SHM include springs, pendulums, and torsional oscillators.