The serpentine belt is a long, winding belt that drives multiple peripheral devices simultaneously, including the alternator, power steering pump, water pump, and AC compressor. It is guided by idler pulleys and kept tight by a belt tensioner. It is a more efficient design than multiple V-belts but introduces a single point of failure; if the serpentine belt snaps, all associated systems (charging, cooling, and steering) fail instantly. Regular inspection for cracking, glazing, or fraying is essential for vehicle reliability.