| Atziluth | Archetypal World (World of Emanations) or Divine World |
| Briah | Creative World or World of Thrones |
| Yetsirah | Formative World |
| Assiah | Manifest World |
These four worlds can be considered as a linear hierarchy, each containing its own full Tree, in which Malkuth in one world becomes Kether of the world below, and Kether of one world becomes Malkuth of the world above. Malkuth is seen as the complementary fulfillment of Kether: the first is Divine Immanence, the latter Divine Transcendence.
An alternative is to view the four worlds as being expressed through a single Tree. Atziluth is expressed through the sefira Kether; Briah through Chokmah and Binah; Yetsirah through the six sefirot Chesed to Yesod; and Assiah through Malkuth. (Some prefer to view Atziluth as acting through both Kether and Chokmah, and Briah as acting through Binah alone.)
Both systems of either one or four Trees are equally valid and are used according to context, rather like the physicist viewing light as a wave of energy or a stream of particles depending on circumstance. A further outlook is that each sefira can be viewed as a whole Tree itself, giving ten Trees and one hundred sefirot. Kabbalistically these numbers can be considered equivalent as, using techniques similar to numerology, 100, 10 and 1 are fundamentally one (1+0+0 = 1+0 = 1).
The fourfold aspect given to each sefira by its existence in each of the four worlds allows application of the Kabbalah to fourfold systems such as the western elements (Fire, Air, Water and Earth), the letters of the Tetragrammaton (Hebrew Name of God: Yod, He, Vau, final He), the Jungian functions and the Minor Arcana of the Tarot. The latter is very important in the
