A Kabbalistic view of creation and existence based upon a division into four levels, illustrated in this verse from the Bible:
"Everyone that is [1] called by My name, and [2] whom I created for My glory, [3] I formed him, yea [4] I made him." - Isaiah-Yeshayahu 43:7
These four levels are called the Four Worlds:
Atziluth, the world of Archetypes or Emanations. (Example: the level of potentialities or "blueprints." In the sperm and ovum are the possibilities for a child.)
Briah, the world of Creation. (Example: the father and mother unite sexually and the embryo of a human being is created.)
Yetzirah, the world of Formation. (Example: the child is formed in the womb for nine months.)
Assiah, the world of Action. (Example: the child is born into the physical world.)