Video explanation
The movement reveals gears, balance and levers; pushers switch the chronograph between running and stopped, while crown actions affect the reserve.
Mainspring energy
Winding stores elastic energy in the mainspring, which the gear train transmits to the timekeeping mechanism.
Escapement meters motion
Balance oscillation and escapement meter energy rather than allowing the gears to accelerate freely.
Chronograph coupling
Starting couples the chronograph train; stopping disengages or brakes it. The model does not represent every caliber.