What is oscillatory motion?
Oscillatory motion refers to the motion in which the object moves back and forth repeatedly about a point called mean position. This is a periodic motion which repeats after some interval of time called the period of oscillation. Therefore, oscillatory motion is motion that is repetitive and which repeats about a mean position.
Oscillation is the repetitive variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states.This motion is known as oscillatory motion. Familiar examples include a swinging pendulum and AC power. The term vibration is sometimes used more narrowly to mean a mechanical oscillation but sometimes is used to be synonymous with "oscillation". Oscillations occur not only in physical systems but also in biological systems, in human society and the brain.