If pitch is the up and down movement of the nose. Yaw is the left and right movement of the nose. This is done with the rudder, the vertical hinge surface on the tail. When we step on the rudder pedals in the cockpit it moves the rudder from side to side. Moving the rudder to the right deflects the tail to the left. Thus causing the nose to swing to the right. A left deflected rudder does the opposite and the nose goes left. This doesn't turn the airplane. It just moves the nose from side to side. This is helpful when turning the aircraft however to counteract what is called adverse yaw or the tendency for the nose initially to swing out opposite the direction of the turn. Adverse yaw is an unavoidable side effect of using the ailerons. The downward deflected aileron on the wing outside of the turn drags that wing rearward. The pilot must compensate for this undesirable yaw.