What is the timing of the timing chain

Timing mainly refers to valve timing. In a narrow sense, it generally refers to the opening and closing time of the intake and exhaust valves and the maximum lift point of the valve.

Translated from English timing.

The opening and closing of the valve is driven by the camshaft, and now the camshaft is driven by the crankshaft through a chain system or a pulley, so the chain system that drives the camshaft is called a timing chain.