True Angle
The true measure in 3D space of the angle between the two line segments.
CView Angle
The measure of the angle as it would appear if viewed from the current construction view (CView).
Current View Angle
The measure of the angle as it appears on the screen (in the current view).
The difference between the True, CView and Current View angles will be more easily understood by looking at the View Indicator. Although by definition all 3 axes are 90º from each other in 3D space, the 2D image on the screen indicates the different angles depending on their orientation.