Periodic motion refers to movement that repeats itself at regular intervals. This type of motion can be observed in various systems, such as a swinging pendulum or a Ferris wheel. The time it takes to complete one full cycle is known as the period, and it remains constant for each cycle. Examples of periodic motion include the oscillation of a spring and the rotation of the Earth around its axis. These motions are predictable and can be described mathematically, making them important in fields like physics and engineering. Understanding periodic motion helps in analyzing many natural and mechanical systems.