An independent four-wheel suspension allows each wheel to move up and down independently of the rest of the suspension. This means that all four wheels of the vehicle will always be in contact with the ground. This constant ground-to-wheel contact means that you, as driver, will have maximum control of the vehicle. If a drive wheel loses contact with the ground, it can not provide driving force to propel the vehicle along the way. If a "steering" wheel loses contact, it loses directional control over the vehicle. Independent four-wheel suspension systems ensure this does not happen.
The suspension system connecting a vehicle-to-wheels body and its tire allows the wheel to move in an essentially vertical direction in response to good surface irregularities, a spring element stores and temporarily releases energy which thus isolates the body shape . A "shock absorber" shock absorber ensures that the oscillation induced by road unevenness or aerodynamic forces that would impair the comfort of the ride and maintenance of the road quickly disappear.
The conventional system provides greater simplicity. They contain systems like rigid axle suspension. They are the most used in heavy vehicles. Suspension is directly using leaf spring therefore have less complexity. In this system both wheels of the vehicle are suspended in combination when the direct axle is suspended. Simplicity is the only advantage, they do not provide an effective suspension.
With the development of technology has emerged a new concept called independent wheel suspension. In this system both wheels are suspended independently as each wheel has its independent suspension system. This provides suspension for the actual road conditions. This system is very complex but has advantages as low weight, far reaching to achieve favorable elasto-kinematic effects, without mass coupling, without suspension parts running through the vehicle. Therefore now a day on most passenger cars this system is used and preferred over the conventional system, providing the soft real drive.