Astral Plane

The astral plane, also called the astral realm, or the astral world, or the soul realm, or the spirit realm, is a plane of existence postulated by classical, medieval, oriental, esoteric, and New Age philosophies and mystery religions. It is the world of the celestial spheres, crossed by the soul in its astral body on the way to being born and after death, and is generally believed to be populated by angels, spirits, or other immaterial beings. In the late 19th and early 20th century, the term was popularised by Theosophy and neo-Rosicrucianism.
Another view holds that the astral plane or world, rather than being some kind of boundary area crossed by the soul, is the entirety of spirit existence or spirit worlds to which those who die on Earth go, and where they live out their non-physical lives. It is understood by adherents that all consciousness resides in the astral plane. Some writers conflate this realm with heaven or paradise or union with God itself, while others do not. Paramahansa Yogananda wrote in Autobiography of a Yogi (1946), "The astral universe ... is hundreds of times larger than the material universe ... [with] many astral planets, teeming with astral beings."
The "World of Al-Ghaib" and the "World of Barzakh" are related concepts in Islam (also the concept of 'âlam al-mithâl "imaginal world" in Sufism). In Judaism, it is known as the "World of Yetzirah", according to Lurianic Kabbalah.

History
Plato and Aristotle taught that the stars were composed of a type of matter different from the four earthly (classical) elements—an ethereal fifth element or quintessence. In the "astral mysticism" of the classical world the human psyche was composed of the same material, thus accounting for the influence of the stars upon human affairs. In his commentaries on Plato's Timaeus, Proclus wrote the following:…