Camber is the measure of the degree of perpendicular offset from the road surface. Caster is the angle of your wheel's pivot, which is attached to the suspension. When this angle is out of alignment, straight-line tracking is affected. Toe refers to the angle of directional difference between the tire and the vehicle's centerline.
The front and rear wheels on your vehicle should always be perpendicular to the ground and parallel to the tire beside it. Routine wheel alignments have the potential to save you money in the long run while promoting optimal vehicle performance.