It just refers to the shuttet speed and FPS.
As you probably know, 360° means the entire time, the frame is exposed.
0° means it is never exposed, 180° half of the time.
With digital shutters you can just take your FPS, for example 24, and calculate the corresponding value.
For 180°, you can double it 24*2=48 so youbget a shutter speed of 1/48s.
For 360° ...