The term for the spinning motion of a planet around its axis is called "rotation." This movement is responsible for the cycle of day and night as different parts of the planet are exposed to the sun. Earth takes approximately 24 hours to complete one full rotation, which is why we experience a full day in this time frame. Various planets have different rotation periods; for example, Jupiter has the shortest rotation period of any planet in the solar system, completing a rotation in just under 10 hours. The concept of rotation is crucial in understanding the dynamics of celestial bodies.