Tire rotation is periodically changing the position of each of the tires on your vehicle. From front to back or side to side.  Rotating your tires regularly gives you a good opportunity to inspect them for any type of damage.  You may have some vibration and need them re-balanced . This is also a good time to check the tread depth on each tire.  It is important to keep the tread depth on your tires uniform because it helps keep traction and handling consistent across all four tires.  Rotating your tires is required in order to maintain the warranty on them. You should rotate your tires as recommended by the vehicle manufacture or every 6000 miles.