The word Kabbalah means "to receive" and the core of this teaching relies on the fact that the spiritual and the physical worlds not isolated from each other, but closely linked. Beause of its high desire to receive, humanity represents not only the bridge between these two worlds, but it also carries the potential to fulfill their unification.
The Tree is a model of the template of the all world, a model of the Universe which carries within its own system of rules and laws. This ancient map teaches us that there are four levels or dimentions of reality: Atziluth, the world of Emanation, Briah, the world of Creation, Yetzirath, the world of Formation, and Assiah, the world of Action. All these levels contain the same essence, even if expressed with a different quality.
This means that all the things and happenings on one level are not only copied in the one below, but they must also have a counterpart in the worlds above. The kabbalistic statement "As above, so below" highlights the concept that everything we see in this world is only a reflection to something occurring beyond outward phenomena.
"In thirty-two mysterious paths of Wisdom did the Lord write...
He created His Universe by the three forms of expression:
Numbers, Letters, Words.
Ten innefable Sephirot and twenty-two basal letters"
Sepher Yetzirah
According to the kabbalistic teaching, the creation occured because of a withdrawal of the Light of the Creator. God manifested the Sephirot which are a sequence of ten energy fields which keep us protected from the full intensity of His Light. Each Sephirah has distinctive qualities, properties and lessons to be absorbed and mastered. The ten Sephirot are the manifestation of states of consciousness, and they act as transformers as we work with them.