A cam mechanism is a mechanical device that converts rotational motion into linear motion. It consists of a rotating element, called a cam, which has a specially shaped profile. As the cam rotates, it pushes against a follower, causing it to move in a specific path. This mechanism is commonly used in engines and machinery to control the timing of movements. The design of the cam can vary, leading to different types of motion for the follower. For example, in an internal combustion engine, the cam controls the opening and closing of valves, ensuring that fuel and air enter the combustion chamber at the right time.