A serpentine is a wider, thicker, updated version of its predecessor, the V-belt. You’re more likely to find a V-belt in an older model, while newer cars have serpentine belts.
Both belts serve the same purpose in your engine: delivering power to your steering, air conditioning, alternator, and other systems. But, auto manufacturers began to favor the serpentine belt over the V-belt because the former is lighter and easier to place back on track. The latter is heavier and more difficult to install.
Plus, the flatter design of the serpentine belt provides greater traction, which generates more power for your engine.