Secondly, we can categorize suspensions by hoe they transfer shock from the road surface:
* A suspension is sprung when the chassis is supported by elstic elastic element attached to the given axle so the shocks from the are partially absorbed.
*A suspension is unsprung when the chassis is supported by the given axle directly so the shocks from the axle are fully transferred to the chassis.
The easiest way to tell a sprung suspension from an unsprung one is by trying to press the vehicle's body down on its wheels. A sprung suspension will make the body yied, while an unsprung suspension will not. This is because a vehicle with unsprung suspension maitains constant ground clearance, which means that the middle of the chassis always stays the sme distance from the ground.
That makes unsprung suspenson commonly used in heavy machinery, as it does not yield under heavy loads