These are buttons Start/Stop, Lap, Reset


Start/Stop - Keyboard Equivalent = Space

Click on 'Start' to start the Stopwatch.  This button will then change and read 'Stop'.  Now click this button to stop the stopwatch.


Lap

This button is only available when the stopwatch is running.  Click on this button to record the time to the tape display.


Reset

This button is only available when stopwatch has been started and stopped.  Click on this button to reset the stopwatch.