This stopwatch measures elapsed time by comparing timestamps rather than counting ticks, so the reading stays accurate even if the browser throttles the refresh — the display simply updates about ten times a second to show tenths. Start begins timing, the same button becomes Pause to freeze the count, and pressing it again resumes from exactly where you left off without losing any accumulated time.
The Lap button records a split at the current total time and lists them newest-first, which is handy for timing repeated intervals such as laps of a track or steps in a process. Reset clears the clock and all recorded laps back to zero. Everything runs locally in your browser with no network calls, and the internal timer is cleared whenever you pause, reset or leave the page.