Here you can get detailed information about a single set of your swim. If you swam with a smartwatch and its hardware allows it, you can view various indicators such as the number of strokes, your heart rate, calories burned, etc. (more about supported smartwatches).
The icon on top gives you an orientation to your performance:
First tracked time for this style.
New personal best.
You have improved your average for this style.
You have worsened your average for this style.
This was an average result.
This set has not been tracked in personal bests, which is usally a good option for technical drills.
Your result seems to be a little bit too quick, because this would be a new world record. Maybe you should consider participating in the Olympics – or edit the result.
If you have selected the set from the personal best page or from the track history, the number shows you the all time rank for this set.
Explanation: These performance indicators where made when you did or edit this swim. They are not updated after every swim, so they provide you an indication of your performance at this time.
Track History: Below the performance data you will find an overview of previous sets you have swum in this style and distance.
In the top menu you can choose to edit the swim this set belongs to (more).