("Formation"): Yetzirah is the third of the four worlds of Creation, wherein the ethereal ?substance? of Beriah is endowed with spirit and generic form; the consciousness of yesh m'yesh; the spiritual abode of the chayot; the origin of ruach in the soul of man. For further explanation see: The Worlds of Abiya.
Yetzirah is the 3rd of 4 worlds in the Kabbalistic Tree of Life, following Assiah and preceding Briah. It is known as the "World of Formation". Within the Western mystery tradition, the different Sephirah in this world are associated with the angels, and it is associated with the suit of Swords in the Tarot.