Alignment refers to an adjustment of a vehicle’s suspension – the system that connects a vehicle to its wheels. It is not an adjustment of the tires or wheels themselves. The key to proper alignment is adjusting the angles of the tires which affects how they make contact with the road. Wheel alignment machines come in different styles
CCD: Charged Coupled Device where the alignment heads attach to the rims or tires with clamps. They create a laser box around the vehicle and with accelerometers detect the angles of toe, camber, and caster
3D: A camera imaging system where targets are attached to the vehicles rims or tires and provide the angles of toe, camber, caster
Touchless: A new style system where no devices are attached to the vehicles rims or tires, but take images of the wheel assembly providing angles of toe, camber, caster. Usually the fastest system available as far as getting initial readings.