Difference between Euler rotation modes

I’m working with BlenRig and notice that some bones are using ZXY Euler for the rotation mode. I’ve experimented with changing some of these bones to XYZ Euler (or some other Euler combination) and am not seeing any obvious difference in the behavior of the bone. Likewise, I’ve done some Python scripting where I controlled bones which were set to miscellaneous variations of Euler, and the bones behaved exactly the same way when I sent over the data to Blender.

What is the purpose of the various Euler modes, and how does it relate to bones in a rig?

some Euler sequences will change how the rotation works but depends which one you use

and don’t forget with rig the up value is Y and not Z if I remember well!

there are some good tut or site to explain all the differences

happy bl

Could you or someone else recommend a good tutorial for this subject? I haven’t been able to find anything that explains this well.