Display of Envelopes
By default, all clips display a level envelope curve. You can view the envelope as three separate envelopes: the fade in part, the sustain part, and the fade out part.
The points on the left and right side of the curve are the fade in and fade out junction points that separate the fade parts from the sustain part.
The envelope curve indicates if points, fade ins, or fade outs have been defined. In addition to the curve, changes in the level envelope are also reflected in the waveform.