Kabbalah literally means "receiving", in the sense of a "received tradition", and is sometimes transliterated as Cabala, Kabbala, Qabalah, or other permutation. Kabbalah esoterically interprets the Hebrew Bible (Tanakh) and classical Jewish texts (halakha and aggadah) and practices (mitzvot), as expressing a mystical doctrine concerning God's simultaneous immanence and transcendence, an attempted resolution to the ancient paradox of how the ultimate Being-"that which is not conceivable by thinking" (Isaac the Blind)-nevertheless comes to be known and experienced by the created world.
Because of the interpretive liberties taken by kabbalistic thinkers, and the possible heresies to which they may easily lead, study of Kabbalah was traditionally restricted to a select few Rabbis and Torah scholars. As Joseph Albo puts it in his Sefer Ha-Ikkarim (II:28, 15th century, trans:Husik), "This is why the science treating of these things is called Kabbalah (lit. tradition), because tradition must be followed in the study and the practice of it, else one is liable to commit an error and to worship as God some one other than the Lord."
The term Kabbalah was originally used in Talmudic texts, among the Geonim (early medieval rabbis) and by Rishonim (later medieval rabbis) as a reference to the full body of the oral tradition of Jewish teaching, which was publicly available. Even the works of the Tanakh's prophets were referred to as Kabbalah, before they were canonized as part of the written tradition. In this sense Kabbalah was used in referring to all of Judaism's oral law. Over time, much of the oral law was recorded, but the esoteric teachings remained an oral tradition. Now, even though the esoteric teachings of the Torah are recorded, it is still known as Kabbalah.
Thus, this term became connected with doctrines of esoteric knowledge concerning God, the human being and the relationship between them. Ontology, cosmogony, and cosmology are the main components of this esoteric lore. The reasons for the commandments in the Torah and the ways by which God administers the existence of the universe are also a part of the Kabbalah.