Wheel alignment is the proper adjustment of ALL the interrelated suspension angles. Camber is adjusted to prevent excessive tire wear and to enhance straight ahead stability. It is measured in degrees and has several methods of adjustment. This is the most critical tire wearing angle. The angle formed by a horizontal line through the plane of one wheel versus a centerline is called the individual toe.
Caster is measured in degrees, from the steering axis to vertical, as viewed from the side.
It is computed in degrees by looking at the camber change of each wheel through a specified steer. There are three types of caster settings. Positive caster angle is when the top of the steering axis it tilted rearward. Negative caster angle is when the top of the steering axis is tilted forward. If the vehicle has unequal caster, it can cause the vehicle to pull from side to side.