A chronograph is a type of watch that includes a stopwatch function, allowing the user to measure elapsed time in addition to displaying the time.
A chronograph is a stopwatch function built into a watch, allowing you to measure elapsed time. A chronometer is a precision timepiece certified by COSC for exceptional accuracy, meeting strict standards of +6/-4 seconds per day. A watch can be both.
Press the top pusher to start timing, press it again to stop, and press the bottom pusher to reset. The chronograph seconds hand sweeps around the main dial, while subdials track elapsed minutes and hours. The watch continues keeping regular time independently.
In quartz chronographs, running the stopwatch function does consume more battery power. However, in mechanical (automatic or manual-wind) chronographs, using the chronograph draws from the mainspring's power reserve but doesn't drain anything permanently—simply wind as needed.