Qabala, Cabala, Kabala, Qabalah, Kabbalah

The Qabala is a system of Jewish mysticism.
Eliphas Levi, a 19th century occultist was the first to link the Tarot with the Qabala, specifically linking the 22 letters of the Hebrew alphabet with the 22 Major Arcana. Subsequent occultists siezed this idea and expanded upon it, including A.E. Waite of the Waite-Smith or Rider deck, Paul Foster Case of B.O.T.A. (Builders of the Adytum) and Aleister Crowley.

The major symbol in the Qabala is the Tree of Life. It is thought to be a blueprint for the Universe.
The Tree of life consists of four worlds, each of which corresponds to one of the four Hebrew letters in the symbol for the name of God, IHVH. The four Worlds are:

Atziluth - The Archetypal World - This is the world of pure Spirit or pure ideas. All other worlds originate here. It is assigned the element Fire and corresponds to the letter I (Yod) in IHVH.

Briah - The Creative World - This is the world where the idea is given form or a pattern. It is assigned the element water and corresponds to the first letter H (Heh).

Yetzirah - The Formative World - This is the world where the pattern is given expression. It is assigned the element air and corresponds to the letter V (Vau).

Assiah - The Active or Material World - This is the world where the idea is given physical form. It also contains the unseen energies of matter. It is assigned the element earth and corresponds to the second letter H (Heh).

The four suits and the four court cards are assigned to the four worlds.

Atziluth - Fire - Kings
Briah - Water - Queens
Yetzirah - Air - Knights
Assiah - Earth - Pages

Knowing these attributions will help you interpret the Court Cards. The King of Wands for example is Fire of Fire; the King of Cups, Fire of Water etc.
"The Witches Tarot" takes the assignments one step further by using the attributes of each world as the way the court card modifies the card following it If you go back to the lesson which discusses the Witches Tarot system, you'll see what I mean.

Qabala, Part 2

Each Major Arcana is associated with a Hebrew letter of the alphabet, although different authors have made different assignments.

A common (though not the only) listing:
Fool Aleph Ox
Magician Beth House
High Priestess Gimel Camel
Empress Daleth Door
Emperor Heh Window
Hierophant Vau Nail or Hook
Lovers Zain Sword
Chariot Cheth Fence
Strength Teth Serpent
Hermit Yod Open Hand
Wheel of Fortune Kaph Closed or Grasping Hand
Justice Lamed Ox Goad
Hanged Man Mem Water
Death Nun Fish
Temperance Samekh Prop
Devil Ayin Eye
Tower Peh Mouth
Star Tzaddi Fish hook
Moon Qoph Back of the Head
Sun Resh Head
Judgment Shin Tooth
World Tau Mark

Each letter also represents a Hebrew word.
These words are also clues to the meaning of the card. The Lovers for example is Zain or Sword. The sword is a tool of division or separation and is viewed as cutting cleanly through to the heart of the matter.
It cuts off what is no longer necessary, thus it implies a choice between what is to be kept and what is to be discarded. Amber Jayanti in "Living the Tarot" calls it "the sword of discrimination".

Qabala Part III

The tree of Life is divided into three pillars; Severity, Mildness and Mercy. On the pillars are arranged the ten Sephiroth. They are:

Kether - The Crown - Aces
Chokmah - Wisdom - Twos, Kings
Binah - Understanding - Threes, Queens
Chesed - Mercy - Fours
Geburah - Strength - Fives
Tiphareth - Beauty - Sixes, Knights
Netzach - Victory - Sevens
Hod - Splendor - Eights
Yesod - Foundation - Nines
Malkuth - The Kingdom - Tens, Pages

Each Sephiroth is on a pillar of the tree. They are arranged in such a way that there are 22 paths between them.
The Major Arcana have been assigned to these paths. The Chariot for example, is assigned the path between Geburah (Strength) and Binah (Understanding), both of which are on the Pillar of Severity. The Sephiroth are the underpinning of the Minor Arcana interpretations.
The fifth Sephiroth (Strength), is the Sephiroth of destruction or tearing down. It's influence is seen in the fives, which are all about strife and conflict, byproducts of tearing down. Understanding the Sephiroth will help you to understand why the Minors have the interpretations they have.

I will not bore you any further with the Qabala. As previously stated, it is a subject to which one could devote a lifetime of study on it's own. It does have a major influence on modern Tarot, however and now when you hear the terms sephiroth, or paths, you will have an idea of what is being discussed.
If you wish to pursue this topic further, an excellent book is "Living the Tarot" by Amber Jayanti. This book incorporates the Qabala into the interpretation of the Major Arcana in a clear manner, and provides affirmations, personal anecdotes from Jayanti and her students, and a series of questions for each Major card.