A drive belt is a flexible loop made of rubber or other materials that transmits power from one component to another in machinery. It connects the engine to various parts, such as the alternator, water pump, and air conditioning compressor, allowing them to function efficiently. Drive belts come in different types, including serpentine belts and timing belts, each designed for specific applications. Regular maintenance is essential, as worn or damaged belts can lead to engine performance issues or failure of connected components.