The Workplane tab > Information panel contains the following:
Properties — Click to display the orientation of the active workplane relative to the world (global coordinate system).
Elevation and Azimuth Angles are the angle of the Z axis of active workplane relative to the global coordinate system.
The Angles are the rotations about the X axis, then Y axis, then Z axis, (in that order), which transform the axes aligned to the global coordinate system to the current workplane.
Angles are given relative to both the global coordinate system and active workplane.