A lap marks one completed boundary without stopping the stopwatch. Its split is the duration since the previous lap, or since zero for lap one. Its total is the elapsed duration since the session began, excluding paused time. Showing both values makes a copied or exported row understandable by itself.
The split is a difference of totals
If lap one totals 00:02:10.000 and lap two totals 00:05:45.500, the second split is 00:03:35.500. LapWatch stores each total when the button is activated and subtracts the previous stored total. It does not estimate a split from the visible digits or the time between table renders.
Statistics use completed splits only
Fastest and slowest compare stored split milliseconds. Average divides their sum by the completed-lap count and floors only the final millisecond display. An unfinished current segment is excluded because it has no completed boundary. Equal splits remain equal rather than receiving a fabricated ranking.
Know what the browser cannot promise
LapWatch is an informal in-page instrument, not an independent clock service. Closing or reloading the page clears every timestamp and lap. Device sleep, browser suspension and operating-system differences can affect what one browser reports. Keep another suitable method whenever the duration matters, and never use this tool for medical, emergency, food-safety, transport, industrial, official, legal or other safety-critical timing. The fixed 99:59:59.999 and 500-lap limits prevent a forgotten tab from pretending to provide unlimited continuity.