A heat sink is a passive cooling device designed to dissipate heat away from a hot surface, typically an electronic component like a CPU, GPU, or power transistor, into the surrounding environment (usually air). Its primary function is to manage and lower the operating temperature of these components to prevent overheating, which can cause throttling, instability, or permanent failure. It works by increasing the surface area in contact with the cooling medium (air or liquid). Heat transfers from the component to the heat sink’s base via conduction, and then from the fins to the air via convection. Effective heat sinks are crucial for reliability, performance, and longevity in electronics, automotive systems, and industrial machinery. They come in various forms, including simple extruded aluminum shapes and complex assemblies with heat pipes and fans.