Caster angle is the angular displacement from the vertical axis of the suspension of a steered wheel in a Mustang, measured in the longitudinal direction. It is the angle between the pivot line (in a Mustang - an imaginary line that runs through the center of the upper ball joint to the center of the lower ball joint) and vertical. Mustang racers sometimes adjust caster angle to optimize their Mustang's handling characteristics in particular driving situations.
Camber angle is the angle made by the steering wheel of your Mustang; specifically, it is the angle between the vertical axis of the wheel and the vertical axis of the Mustang when viewed from the front or rear. It is used in the design of steering and suspension. If the top of the wheel is farther out than the bottom (that is, away from the axle), it is called positive camber; if the bottom of the wheel is farther out than the top, it is called negative camber.