A rear shock is a component of a vehicle's suspension system, primarily found in motorcycles and mountain bikes. Its main function is to absorb impacts from rough terrain, providing a smoother ride and better control. The rear shock helps maintain tire contact with the ground, improving traction and stability. Rear shocks can be adjustable or non-adjustable, allowing riders to customize their settings based on riding conditions. They typically consist of a spring and a damper, which work together to manage the compression and rebound of the suspension. Proper maintenance of the rear shock is essential for optimal performance and safety.