Difference between euler and yaw, pitch and roll in DMP6 example

[Jcunha]

Hello, I would like to know the difference between the output Euler angles and the output yawpitchroll in the DMP6 example from Jeff Rowberg library. The details I would like to know are in terms of how they both work, their frames of reference, fixed or mobile referential and the sequences used like XYZ or ZYX etc. Thank you.