Final answer:
Precession is the circular movement of the spin axis of a spinning object around another axis due to an applied torque. It is different from spin, which is rotational motion about the object's center of mass. Examples include the Earth's Precessional motion and a spinning gyroscope.
Step-by-step explanation:
The angular movement of the spin axis of an object around an axis fixed in space is known as precession. This phenomenon occurs when a gyroscope or spinning object experiences a torque that is applied to the system, causing the axis of the spinning object to trace a circular path around a secondary axis. For instance, the Earth itself acts as a gigantic gyroscope with its angular momentum aligned along its axis, pointing towards Polaris, the North Star. Over a very long period of time, the spin axis of the Earth precesses, tracing the surface of a cone, commonly referred to as the precessional motion.
Spin, in contrast, is defined as the rotational motion of an object about its center of mass or about an axis that goes through the center of mass. For example, the Earth spinning on its own axis is a form of spin. When torque is applied to a spinning object like a gyroscope, precession occurs around a vertical axis since the torque is always horizontal and perpendicular to the object's angular momentum.