Front Strut is basically a shock absorber with a spring coil for additional support. The front wheels have the extra weight of the engine and need extra support to absorb shock from the road. The shock absorber has a piston and a cylinder that contains a gas or liquid substance. The spring is attached to the piston. When you drive over a bump, the piston inside the cylinder moves up and down against the gas/fluid and the spring, absorbing the shock from the bump. Older cars may have shock absorbers at all four wheels. Faulty or damaged struts affect the ride comfort as well as the braking effectiveness.