No answer, I close the thread.
I finally found what detents are.
They are the actions for providing haptic feedback, notably in the crown.
Now what is type 4 here, in the context of simulator ???
Apple Watch Series 4 provides haptic feedback for the Digital Crown, creating a more tactile experience as the user scrolls through content. By default the system provides linear haptic detents—or taps—as the user rotates the crown. Some system controls, like table views, provide detents as new items scroll onto the screen.
Use the default haptic feedback. If haptic feedback doesn't feel right within the context of your app—for example, if the linear detents don’t match your app’s animation—disable the detents. You can also adjust the haptic feedback behavior for tables, letting the table use linear detents instead of the row-based detents. For example, if your table has rows with significantly different heights, linear detents may produce a better feel.