...while Beriyah, Yetzirah and Asiyah serve to bring forth the offshoots of Atzilut. This is the defining quality of Beriyah, Yetzirah and Asiyah – that they execute the functions of Atzilut. Each one individually brings forth the offshoot suited to it... i.e. they execute and actualize the functions of Atzilut, each world according to its individual nature, institutions and level of existence. And things proceed stage by stage on a scale, for the power produced by Yetzirah is less than that produced by Beriyah.
But besides their different levels, each has its own individual aspects and produces offshoots in accordance with its intrinsic nature. (For example, besides the fact that Yetzirah in itself is a level lower than that of Beriyah, it has its own unique aspects, such as angels.) But their strength is considered on a relative scale.