In short, a chronograph watch is simply a timepiece that can be used as a stopwatch.
The chronograph watch works by pushing a start button to begin recording time, and then by pushing the same button to stop the recording. The button is typically located at the two o’clock position, but it can vary. It is then reset by pushing a button typically at the four o’clock position.
The watch will typically have three dials to display the time elapsed. A minute dial, an hour dial, and a dial for seconds. Their locations vary depending on the watch manufacturer but it is common to see these dials at three, six, and nine o’clock so the look is symmetrical.
Most chronograph watches will also have a tachymeter which involves the caculation of time. It can be used to compute a speed based on travel time or the measure of distance based on speed.
If you want to time yourself running a quarter mile, or how long it takes your coffee to be brewed, a chronograph watch will serve you well.