The Four Worlds are the comprehensive categories of Spiritual Realms in Kabbalah in the descending chain of Existence. The concept of “Worlds” denotes the emanation of creative Lifeforce from the Ein Sof Divine Infinite, through progressive, innumerable Tzimtzumim.
Atziluth (אֲצִילוּת), meaning World of Emanation. On this level the light of the Ein Sof (Infinite Divine “Without End”) radiates and is still united with its source. This supernal revelation therefore precludes the Souls and Divine Emanations in Atzilus from sensing their own existence. In Atzilus the 10 Sephiroth emerge in revelation, with Chochma (Wisdom) dominating, all is nullification of Essence to Divinity, not considered created and separate. The last Sephirah Malchut (Kingdom) is the “Divine Speech” of Genesis 1, through which lower Worlds are sustained.
Beri'ah (בְּרִיאָה), meaning World of Creation. On this level is the first concept of Creatio ex Nihilo, however without yet shape or form, as the creations of Beriah sense their own existence, though in nullification of being to Divinity. Beriah is the realm of the “Divine Throne”, denoting the Sephiroth configuration of Atzilus descending into Beriah like a King on a Throne. The Sephirah Binah (Understanding) predominates, Divine intellect. Also called the “Higher Garden of Eden”. The Highest Ranking Angels are in Beriah.
Yetzirah (יְצִירָה), meaning World of Formation. On this level the created being assumes shape and form. The emotional Sephiroth Chesed to Yesod predominate, the souls and angels of Yetzirah worship through Divine emotion and striving, as they sense their distance from the Understanding of Beriah. This ascent and descent channels the Divine vitality down through the Worlds, furthering the Divine purpose. Therefore, in Yetzirah are the main angels, such as Seraphim, denoting their burning consummation in Divine emotion. Also called the “Lower Garden of Eden”.
Assiah (עֲשִׂיָּה), meaning World of Action. On this level the creation is complete, differentiated and particular, due to the concealment and diminution of the Divine vitality. However, it is still on a spiritual level. The angels of Asiyah function on the active level, as the sephirah Malchut (fulfilment in Kingship) predominates. Below spiritual Asiyah is Asiyah Gashmi (“Physical Asiyah”), the final, lowest realm of Existence, our material Universe with all its creations. The last two Sephiroth of Asiyah channel the Lifeforce into Physical Asiyah.