LightWave allows lights and the camera to automatically rotate to face an object. The Track plugin extends this ability, additionally allowing objects and bones to track. You can also track using any of the 6 object axes, not just the single +Z axis LightWave uses. You can also restrict rotations if necessary. A tank turret can rotate to point at a target, but it won't pitch up onto its edge if the target climbs a hill above the tank. Finally, you can add delays to the tracking, which is useful for gun turrets tracking fast targets.