The Four Worlds (Hebrew: עולמותʿOlāmot, singular: ʿOlāmעולם), sometimes counted with a primordial world, Adam Kadmon, and called the Five Worlds, are the comprehensive categories of spiritual realms in Kabbalah in a descending chain of existence.
The concept of "Worlds" denotes the emanation of creative lifeforce from the Ein Sof or Godhead through progressive, innumerable tzimtzumim or concealments. Kabbalists identified the names of these worlds from Isaiah 43:7, "All who are linked to My name, Whom I have created, Formed, and made for My glory (Biblical Hebrew: כֹּ֚ל הַנִּקְרָ֣א בִשְׁמִ֔י וְלִכְבוֹדִ֖י בְּרָאתִ֑יו יְצַרְתִּ֖יו אַף־עֲשִׂיתִֽיו׃, romanized: Kol hanniqrā b̲išmi wəlik̲b̲od̲i bərāt̲iw yəṣartiw ʾap̲-ʿăśit̲iw.)". The names are thus Beri'ah "Creation," Yetzirah "Formation," Assiah "Action," and Atziluth "Emanation." Below Assiah, the lowest spiritual world, is the Assiah gashmi "Physical Assiah," the physical universe, which enclothes the last two sefirot, Yesod and Malkuth.[1] Collectively, the Four Worlds are referred to as אבי״עAviyaʿ after their initial letters. In addition to the functional role each world has in the process of creation, they also embody dimensions of consciousness within human experience.