Caster angle is a suspension alignment setting. It is the angle of the steering pivot axis when viewed from the side of the wheel. If the axis tilts backward, it is positive caster; if it tilts forward, it is negative caster. Positive caster is standard on modern cars. It acts like the casters on a shopping cart, pulling the tires straight forward when driving and forcing the steering wheel to snap back to center after you complete a turn.
Incorrect caster will not cause tire wear on its own, but it destroys handling. If caster is too low, the steering will feel light, twitchy, and wander on the highway. If caster is unequal between the front wheels, the car will pull constantly toward the side with the lower caster angle.