A physical pendulum is an object that swings back and forth around a pivot point due to the force of gravity. Unlike a simple pendulum, which consists of a mass on a string, a physical pendulum can have any shape and mass distribution. Its motion is influenced by its moment of inertia and the distance from the pivot to its center of mass. The period of a physical pendulum can be calculated using the formula T = 2\pi \sqrt\frac{Imgd} , where T is the period, I is the moment of inertia, m is the mass, g is the acceleration due to gravity, and d is the distance from the pivot to the center of mass. This concept is important in fields like physics and engineering, where understanding oscillatory motion is crucial.