Esotericism
The terms esoteric and esotericism (from Greek esōterikós "inner") refer to claimed knowledge understood by or meant for only a select few. The claimed knowledge may be associated with occultism and/or mysticism.
Some organizations are, covertly or overtly, divided into 2 sections—the exoteric "outer"or "public face" and the esoteric or "inner". There may also be several different esoteric levels. Examples are many fraternal organizations, such as Freemasonry, which have higher and higher levels of initiation as one progresses.
