Essentially, a stop clock is a timing device used to measure short time intervals with high accuracy. Moreover, it typically records time in seconds and fractions of a second (e.g., 0.1 s or 0.01 s).

Operated by pressing a button to start, stop, and reset, it allows precise control during experiments.

In physics labs, it is used to:

Measure the time period of a pendulum
Record reaction times or durations in motion experiments
Time events in free fall or oscillations