Yahweh and Elohim, Yahweh is God emanating, and Elohim is God creating; when Elohim is divided from Yahweh, Elohim becomes the Demiurge. Yahweh is the Olamot-Universes of Adam Kadmon and Atzilut, the Realm of Yichud (Unity), and Elohim is the Olamot of Beriyah, Yetzirah and Asiyah, the Realm of Perud (Separation).
This corresponds to the Pleroma and the Entirety, respectively. On account of the Ignorance, a separation appears to exist between the Pleroma of Light and Entirety, but this is an illusory appearance. Nevertheless, the experience of separation is, in effect, relatively real to the extent that unenlightened beings experience separation – this unenlightened condition is “the separation of Elohim from Yahweh.”
Underlying this saying is the basic teaching that all of our concepts about the beginning are fundamentally in error, for there is no “beginning.” Likewise, all of our concepts about God are not God as God Is – whatever we think God is, that is the Demiurge (Ignorance).
This does bring into play the principle of Tzimtzum, the restriction of God’s presence and power – in effect, Ignorance is the operative principle of the Tzimtzum; hence, the “Demiurge.”
Elohim is the divine name that corresponds to restriction, thus the principle of the Demiurge is the manifestation of Elohim.