Yaw is a type of side-to-side movement that is commonly seen in aircrafts. It is a rotational motion around the vertical axis, and is usually caused by a change in the direction of the airflow. YAW is also used to describe the movement of a ship or other vehicle when it turns from side to side. In addition, YAW can be used to refer to the movement of a person's head or body when they turn their head or body from side to side.