Both rotary axes move the head.
With head– head machine tools, typical angular limits are:
X 
60
Z 360
The machine tool Z limits are equivalent to the Azimuth angle or the angular limits in the XY plane. The Z limit of 360 translates to Azimuth angle limits of 0 to 360.
The machine tool X limits are equivalent to the angle above the XY plane. The machine tool measures the angular range relative to the Z axis and PowerMill measures it relative to the XY plane. So, the angle required for the limit is the complementary angle to the one given for the machine tool. This is described in more detail in Table – Table. The X limit of 60 translates to Elevation angle limits of 30 to 90.
The machine tool's X angle range = 
60, PowerMill's elevation angle range = 30 to 90.
If you select a Mode of Remove toolpath this machines:
Select Draw Limits to see the machinable portion:
Alternative typical Head - Head machine tool angular limits are:
-
X -50 to +60
-
Z 360
This translates to Azimuth Angle limits of 0 to 360 and to Elevation Angle limits of 30 to 90. In this case, although the machine tool limits appear to be different to those in the first Head - Head example, the PowerMill angular limits are in fact the same. This happens because rotating the head 180 about Z then gives you the complete range.