Belts

• Belts are continuous strips of flat or grooved material such as rope, leather or rubber.
  
  

Pulleys

• Pulleys, like gears, are wheels used to build machinery. Unlike gears, they do not have teeth around the edge. This means that they cannot drive one another, but must be turned by something else such as a drive belt.
  
  

Drive Belts

• Drive belts transmit rotary motion, usually through the friction between the belt and the pulley it drives. Multiple drive belts can be connected to a pulley.
  
  

Advantages

• Drive belts are easy to maintain. They do not require lubrication and they are fairly quiet.
  
  

Alternator Belts

• A car's fan or alternator belt is a drive belt linking the crankshaft with the alternator. It transmits power from the turning crankshaft to the alternator, where it is converted to electrical energy. This is stored in the battery and runs all the electrical systems.