Unexplained difference in Rotation values!?


I’m doing the Humane Rigging tutorial and when I rotate the parent cube-empty, the Transform Y value is different from the value in the header as you can see in the image below.

Can anyone explain this to me please?
I’m using Blender 2.74.
Is this a bug, or am I missing something?

The rotation value in the [N] panel ‘stores’ your transformation information, so if you rotate that sphere by 90° on X axis, that’s what it’ll say (if done so in object mode). The number in the heading is usually the number you’re rotating by in that specific transformation.

Thanks Curtis,
I see … So now when I press R-Y-Y to rotate on the local axis for instance, then the values are the same.
(I should have known it had something to do with world-local.)