SW simulation Shear Stress direction convention?

Good Day everyone,

Quick question...I would like to know how is it that the SW Sim results wrt shear stress is interpreted.

For example: I'm doing a simple torsion test. For the Shear Stress Plot, TXZ: Shear in Z Direction on the YZ plane, I get this...

Now i understand this is the YZ plane I'm looking at here, but what do they mean by 'Shear in the Z Direction'? To me, it seems as like the shear is in the Y direction here.

Can anyone clarify this for me?

Thanks,

David

SolidworksSimulation