The timing chain functions in the same way a timing belt does. The difference between your two is simply the material and location. One is made from metal and the other, a reinforced rubber. Though timing chains were used first, belts were presented into vehicles in the 1960s. Belts are quieter and due to their material, less expensive to create. Timing chains are housed within the engine and receive lubrication from engine oil and can last a long time, while timing belts can be found beyond the engine and tend to dry and crack. Within the last couple of years, however, more vehicle manufacturers have integrated timing chains back into some vehicles with vast improvements like a reduction in noise and vibrations, different then a timing belt not all water pumps are powered by the timing chain. Verify your owner’s manual to determine what kind of timing operation your vehicle utilizes because they may vary from year to yr and by a car manufacturer.