Suspension refers to the system of components of a vehicle which control its balance during its ride.
It mainly has two basic functions involved in it. One is to control the balance or handling of the car (automobile) and the second one is to prevent any friction, sounds, or any odds between the parts of vehicle which move during ride.
A more appropriate definition of Suspension of four-wheel automobiles by Wikipedia is:
Suspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels and allows relative motion between the two.
When the talk is of car’s performance, people normally think of horsepower, torque and zero-to-60 acceleration. But all of the power generated by an engine is useless if the driver can’t control the car. That’s why automobile engineers turned their attention to the suspension system almost as soon as they had mastered the four-stroke internal combustion engine.
The job of a car suspension is to maximize the friction between the tires and the road surface, to provide steering stability with good handling and to ensure the comfort of the passengers. So it is a basic and most essential component of an automobile system, and has a place of heart in a car, without which it would be considered dead.