On App Open: All the time between 'app launched' and 'track started'. If you don't enter a track all music (while the app is in the foreground) is controlled by this one.
During Playback: For tracks that don't have background music already embedded. If the track is playing and the app is closed, music plays throughout your meditations. This is especially helpful if you’re doing a longer meditation with more space between readings.
After Playback: Completion screen and any navigation of the app after listening to a track. (This one controls music after meditations end)
Outside the app: If the app is closed but no track is playing. If you want background music even when not using the app.