A pendulum is a weight suspended from a fixed point that swings back and forth under the influence of gravity. It typically consists of a mass, called a bob, attached to a string or rod. When the bob is pulled to one side and released, it moves in a regular, repeating motion, creating a rhythmic swing. Pendulums are often used in clocks, such as the famous Foucault pendulum, to demonstrate the passage of time. They also play a role in physics experiments, illustrating concepts like harmonic motion and gravity. The predictable movement of a pendulum makes it a valuable tool for various scientific applications.