What is the primary purpose of automotive shock absorbers?

Suspension system: the components between the vehicle's body/frame and the wheels that allow the wheels to move up and down independently while supporting the vehicle, absorbing road shocks, and maintaining tire contact with the road. Key components: (1) SPRINGS — SUPPORT the vehicle's weight; absorb impact energy of bumps; types: COIL SPRINGS (most common today, helical wound spring steel), LEAF SPRINGS (older cars, still on most trucks rear; layered steel strips), TORSION BARS (some trucks/SUVs; bar twists when wheel moves), AIR SPRINGS (luxury vehicles, large trucks; pressurized air bag, adjustable height). Springs alone would cause continuous bouncing — they don't dissipate energy, just store and release it; (2) SHOCK ABSORBERS / DAMPERS — DAMP spring motion; oil-filled (or gas-charged) cylinders with pistons; resist motion through oil flow through small orifices; convert kinetic energy of suspension motion into heat in the oil; without shocks, springs would oscillate after each bump, making the car unstable and uncontrollable. Tires would lose contact with the road, reducing steering, braking, and traction. (3) STRUTS — combined spring and shock absorber in one unit; also serve as structural component of the suspension (locating the wheel); MacPherson strut is most common front suspension design; (4) CONTROL ARMS — link wheel hub to chassis; allow up-down motion; control wheel position; (5) BALL JOINTS — allow control arms to pivot; (6) BUSHINGS — rubber/polyurethane cushions in suspension joints; isolate vibration; (7) SWAY BAR (anti-roll bar) — torsion bar connecting left and right wheels; resists body roll in turns; (8) STEERING LINKAGES — connect steering wheel input to front wheels (tie rods, etc.). Common suspension designs: (1) MACPHERSON STRUT — strut + lower control arm; simple, compact; most cars; (2) DOUBLE WISHBONE / DOUBLE A-ARM — upper and lower control arms; better handling; performance and luxury cars; (3) MULTI-LINK — multiple control arms; precise wheel control; performance and luxury; (4) SOLID AXLE — older trucks, off-road; whole axle moves together; durable but less independent. ALIGNMENT: angles of wheels relative to chassis. CAMBER — tilt inward/outward viewed from front; negative (top in) for cornering; CASTER — steering axis tilt viewed from side; affects steering feel and self-centering; TOE — wheels pointing in/out viewed from above; even slight misalignment affects tire wear and handling. Worn shocks: bouncing more than 1-2 times after compression; uneven tire wear; nosediving under braking; poor handling. Tested with 'bounce test': push down corner of car, release, observe if it returns to rest in 1-2 bounces (good) or bounces continuously (worn). Modern systems: ADAPTIVE/ACTIVE SUSPENSION (electronically variable damping); MAGNETORHEOLOGICAL (oil viscosity changes with electric field); AIR SUSPENSION (variable height); each adapts to road and driving conditions.