Directional tires must always spin in one direction. They have to be kept on the same side of the vehicle and not rotated to the other side. For example, the left front tire may only be rotated to the left rear. The same is true for the right front tire, it may only be rotated with the right rear.
This is because of the tread pattern. It is designed to channel water away from the center of the tire and outwards. They're designed to improve performance and are usually found on sport editions. The tread on these tires will appear as a V with the tip of the V pointing toward the front of the vehicle.
These tires have a directional arrow located on the sidewall and pointing toward the front of the vehicle. This is important when mounting or rotating. Always make sure the arrow is pointing toward the front of the vehicle. When rotating, never crisscross these tires. The idea is to achieve better channeling of water and a reduced chance of hydroplaning on wet surfaces. The tread pattern is designed to improve the vehicle’s traction on wet surfaces.