Cambelt replacement tends to be an exercise that appears to make little difference to how a car runs.
A timing belt, timing chain or cambelt is a part of the engine that synchronises the rotation of the crankshaft (bottom end) and the camshaft (top end) so that the engines valves open and close at the correct times during each cylinders intake and exhaust strokes. The timing belt or chain is also critical to preventing the piston from striking the valves. A timing belt or cam belt is a belt that usually features teeth on the inside surface, while a timing chain is a roller chain.
It is important that you know the change interval of your timing belt/cambelt as going over the manufacturers’ recommendation can lead to a slipped or snapped belt. In many cases this can require a new engine or engine build costing hundreds if not thousands of pounds.