From the Hebrew word QBL meaning 'an oral tradition', the esoteric and mystical division of Judaism. The Kabbalah presents a symbolic explanation of the origin of the universe, the relationship of human beings to the Godhead, and an emanationist approach to creation whereby the Infinite Light manifests through different sephiroth on the Tree of Life. Although the central book of the Kabbalah, the Zohar, was not written down until around 1280 -- probably by Moses de Leon-- the Kabbalah has spiritual links with Gnosticism and other early mystical cosmologies.
 
In the Kabbalah, all manifestations are said to have their origin in the Ain Soph Aur and the successive emanations of the Godhead reveal aspects of his divine nature. The system is thus monotheistic in essence, but allows for the tenfold structure of the sephiroth upon the tree of life. The emanations as they proceed down from the  Godhead to the manifested world, are:
KETHER (The Crown)
CHOKMAH (Wisdom)
BINAH (Understanding)
CHESED (Mercy)
GEBURAH (Power)
TIPHARETH (Beauty & Harmony)
NETZACH (Victory);
HOD (Splendor)
YESOD (Foundation)
MALKUTH (The Kingdom)

Occultists in the Hermetic Order of the Golden Dawn use the Kabbalistic Tree of Life as a matrix or grid for comparing the Archetypal images of different mythologies that could be adapted to Ceremonial Magic.

For example, the Merciful Father (Chesed) has parallels in other pantheons, namely Odin (Scandinavia); Zeus (Greece);Jupiter (Rome); and Ra (Egypt). This system of comparison became known as mythological correspondences. It has become common in the occult tradition to link the ten sephiroth of the Tree of Life with the 22 cards of the Major Arcana of the Tarot.

The first Sephira is called the Crown or the Inscrutable Height; the second is called Wisdom; the third is called Understanding;  the fourth is called Love, Mercy or Majesty; the fifth is called Severity, Justice or Fear; the sixth is called Beauty; the seventh is called Victory; the eighth is called Splendour or Glory; the ninth is called Foundation; and the tenth is called the Kingdom.
 
The Ten Sephiroth have a direct relationship with the Sun, Moon, Planets and Elements.  Pluto corresponds with Kether or the Crown; Uranus corresponds with Chokmah or Wisdom; Saturn corresponds with Binah or Understanding; Jupiter corresponds with Chesed or Mercy; Mars corresponds with Geburah or Severity; the Sun corresponds with Tiphareth or Beauty; Venus corresponds with  Netzach or Victory; Mercury corresponds with Hod or Glory; the Moon corresponds with Yesod or the Foundation; and the Four Elements of Fire, Water, Air, and Earth correspond with Malkuth or the Kingdom.  All the planets have been listed but Neptune.  Neptune corresponds with the so-called Invisible Sephira on the Tree of Life.  This hidden Sephira is called Daath or Knowledge and is located in the Abyss below Chokmah and Binah on the Tree. It was the original location of Malkuth before the so-called Fallof Man.
 
The Ten Sephiroth correspond in Tarot with the Minor Arcana cards.  The four aces are Kether; the four twos are Chokmah; the four threes are Binah; the four fours are Chesed; the four fives are Geburah; the four sixes are Tiphareth; the four sevens are Netzach; the four eights are Hod; the four nines are Yesod; and the four tens are Malkuth.  Each of these Minor Arcana cards represent the operation of one of the Sephiroth in a particular element.  For instance, the Six of Wands represents the operation of Tiphareth in the element of fire; for the Wand is a symbol of fire.  The Cup cards represent the operation of the Sephiroth in the element of Water;  the Sword cards represent the operation of the Sephiroth in the element of Air; and the Coin or Pentacle cards represent the operation of the Sephiroth in the element of Earth.

Definitions

QBL: Hebrew word meaning 'from mouth to ear', thereby signifying a secret oral tradition. It is the meaning of Kabbalah.

Ain Soph Aur: Hebrew expression meaning 'the limitless light'.

Tree of Life: The Tree consists of Ten spheres, or sephiroth, through which according to mystical tradition--the creation of the world came about. The sephiroth are aligned in three columns headed by the supernals (Kether, Chokmah, Binah) and together symbolize the process by which the infinite light (Ain Soph Aur) becomes manifest in the universe.  Beneath the Supernals are the 'Seven days of Creation': Chesed Geburah, Tiphareth, Netzach, Hod, Yesod, and Malkuth. Taken as a whole, the tree of life is also a symbol of the archetypal man -- Adam Kadmon, and the sephiroth have a role resembling that of the chakras in yoga. The mystical path of self knowledge entails the rediscovery of all the levels of ones being, ranging from Malkuth (physical reality) to the infinite source. With this in mind, the medieval Kabbalists divided the Tree of Life into three sections of the soul: NEPHESCH (the animal soul) corresponding to the sephiroth YESOD to RUACH (the middle soul), corresponding to the sephiroth from HOD to CHESED NESCHAMAH ( the spiritual soul) corresponding to the Supernals --especially BINAH. Practitioners of western magic, who use the Tree of Life as a glyph for the unconscious mind, sometimes distinguish the magical path (which embraces all ten sephiroth) from the mystical path of the middle pillar, which is an ascent from Malkuth through Yesod and Tiphareth to Kether on the central pillar of the Tree.

Zohar: 'The Book of Splendor'--the principal book of the Kabbalah. It is thought to have been written by Moses de Leon and was first circulated around 1280-1290, in Guadalajara. It included commentaries on the Torah.

Gnosticism: Gnosis is a Greek term for 'knowledge'. The term Gnosis applies to certain religous sects that emerged during the early formative years of early Christianity, and which belived in 'Hidden Spiritual Knowledge'. The main factor that differentiated them from Chritianity was their emphasis on knowledge rather than faith.  The Christian churche fathers considered the Gnostics Heretical, or Heretics.

Sephiroth: The ten speres or emanations on the Kabbalistic Tree of Life, a symbol which depicts the divine energy of creation proceeding like a lighting flash through ten different stages, culminating in physical manifestation. The sephiroth represent levels of spiritual reality both in the cosmos and in people because the Tree, metaphorically, is the 'Body of God', and people are created in his image. The Tree is sometimes shown superimposed on the body of the archetypal man.

Kether: The first Emanation on the Tree of Life. Occultists indentify Kether as the state of consciousness where creaton merges with the veils of nonexistance. Kether lies on the Middle Pilalr and trancends the duality of Chokmah (male) and Binah (female), which lie immediately below on the Tree. It is therefore symbolized in mystical tradition by the heavenly Androgyne (male and female united in one), and represents a state of mystical Transcendence and union with the Supreme. It is compared to Satori and Nirvana.

Chokmah: The second emanation on the Tree of Life, following Kether. Occultists identify Chokmah with the Great Father, the giver of the seminal spark of life which is potent only until it enters the womb of the Great Mother, Binah. From the union of the Great Father and Great Mother come forth all the images of creation. Chokmah is associated with such deities as Kronos, Saturn, Thoth, Atum-Ra,and Ptah, in other pantheons.

Binah: The third emanation on the Tree of Life. Occultists identify Binah with the Great Mother in all her forms. She is the womb of forthcoming, the source of all the great images and forms that manifest in the universe as archetypes. She is also the Supreme female principal in the process of Creation and, via the process mythological correspondences, is associated with such deities as The Virgin Mary, Rhea, Isis, and Demeter.

Chesed: The fourth emanation on the Tree of Life. Occultists identify Chesed as the ruler (but not Creator) of the manifested universe; and he is characterised as stable, wise, and merciful by contrast with his more dynamic opposite, Geburah.  Chesed is asscociated with Gods Zeus (Greek), and Jupiter (Roman).

Geburah: The fifth emanation on the Tree of Life. Geburah is often associated with MARS, the Roman God of War, and represents Severity and Justice. The destructive forces of the sphere of Geburah are intended to have a purging, cleansing effect on the universe. Geburah represents the Creator God, who applies discipline and presicion in governing the cosmos and removes unwanted or unnecessary elements after their usefullness has passed. Geburah is reflected in the Chariot(eer) of the Tarot.

Tiphareth: The sixth emanation on the Tree of Life.It is the sphere of beauty, harmonizing the forces of mercy(Chesed) and Judgement (Geburah), higher on the Tree. Occultists identify Tiphareth as the sphere of spiritual rebirth, and ascribe to it the Solar Deities such as Ra, Apollo, and Mithra as well as Osiris and Jesus Christ. The tarot card Temperance identifies the direct mystical ascent to Tipareth from Malkuth(the physical).

Netzach: The seventh emanation on the Tree of Life. Netzach is regarded as the sphere of creativity, subjectivity, and the emotions -- a very clear contrast to the sphere of Hod, which represents intellect and rational thought. Netzach is the sphere of Love, and spiritual passion and is therefore associated with such deities as Aphrodite, Venus, Hathor, and others that personify these qualities.

Hod: The eighth emanation on the Tree of Life. Hod is associated with the planet Mercury and represents intellect and rational thought. It also represents the structuring and measuring capacities of the mind as opposed to the emotion and intuitional aspects of Netzach. Hod has no exact parallel in the Tarot, but is closely linked to the card Judgement, ascribed to the path between Hod and Malkuth.

Yesod: The ninth emanation on the Tree of Life. Yesod is associated with the Moon and the element Water. Regarded as a Female sphere, it is the seat of sexual instinct and corresponds to the Genitals Chakra on the archetypal man. On the Tree of Life Yesod has the function of channelling the energies of the higher down to the earth below(Malkuth). Occultists associate Yesod with the Astral Plane, because if the sephiroth above Malkuth are regarded as a map of the unconscious psyche, Yesod is the most accesible area of the mind. Because Yesod is the sphere of Fertility and Lunar imagery, it is identified with Witchcraft and Goddess Worship.  It also the so called 'animal soul' known by Kabbalists as Nephesch.

Malkuth: The tenth emanation of the Tree of Life. Malkuth is associated with the Goddesses of the Earth especially Persephone (Greece), Prosperina (Rome), and Geb (Egypt). Malkuth is the domain of the manifested universe, the immediate enviroment, the plane of physical reality. As a consequence, all 'inner journeys of consciousness' begin symbolically in Malkuth; it is particularly appropriate, for example, that the myth of the rape of Persephone confirms her both as queen of the underworld and as a Lunar Goddess. From an occult point of view, the Underworld equates with the Lower unconscious mind, and the Moon, represented by the sphere of Yesod, is the first Sephirah reached on the inner mystic journey up the Tree of Life. Malkuth is closely linked with the Tarot card The World.

~from various sources