V-Belts are the standard drive belts used for decades to drive many engine components including the water pumps, alternators, a/c compressors, and power steering. As opposed to the newer serpentine belts, V Belts are used to drive each component independently. They are called V Belts because the cross section resembles a trapezoid, or v shape, which creates a wedge action with the grooves on the pulley or sheave to prevent slipping off or misalignment.
Drive belts become worn over time and can cause major issues if they break. Be sure to check for cracks in your drive belts to prevent component failure and engine overheating. The advantage that V Belts have over serpentine belts is that a broken belt can simply mean that a single component fails which doesn't necessarily mean you can no longer operate the equipment or vehicle.
For instance, if your drive belt running your air conditioning system breaks, the vehicle operator will get hot but the vehicle will still operate. However, if the drive belt powering the alternator breaks, your alternator will be charged improperly and could cause your engine to overheat. If the serpentine belt breaks, all components that it drives will fail. V belts are more complicated to change out since there are multiple drive belts to change. It can also be difficult to get the right tension on your individual drive belts which can cause your engine to squeal and potentially overheat.
It is recommended to check your V belts every 30,000 miles and be sure to change them at the first sign of wear.