An oscillating movement is created when the pendulum is moved back and forth.
The center of oscillation is a place on the pendulum where the mass is concentrated and the period remains constant.
This point is on the same side of the axis as the Centre of mass, and its distance from the axis equals the equivalent length of the compound pendulum Where is the mass of the pendulum, is the distance of the center of mass to its rotation, and is the moment of inertia about the axis.
The shorter the time period of oscillation, the higher the frequency of the pendulum