The serpentine belt, occasionally also referred to as a drive belt or fan belt, is found on the exterior of the engine. It is responsible for delivering power from the engine to different important parts of your vehicle, such as the alternator or your power steering. On the flip side, the timing belt is responsible for making sure the interior of the engine is operating properly. It ties the upper and lower engine components together and ensures that it’s always working. In other words, it’s pretty important. You want to make sure to take care of either belt right away if you think something might be wrong.