Planar Divergence

Planar Divergence or rather, the The Wheel Cosmology, is the theory that explains the place of the planes in the Astral Plane and how they fit together.

The Cosmology

Three Material Planes

This is the physical world where mortals dwell, also called the Prime Material Plane In addition, the Feywild and Shadowfell are material planes, which somewhat are a kind of a miror of the prime material plane.

Two Transitive Planes

These planes act as 'bridges' between other dimensions. The Ethereal Plane allows for travel between realities, the Astral Plane serves as the realm of dreams and souls.

Four Inner Planes

The Four Elemental Planes

Fire, Air, Earth, and Water each have their own dedicated planes, representing raw elemental power.

The Sixteen Outer Planes

These vast, layered planes are the homes of deities and powerful outsiders. Each plane embodies a specific alignment, influencing those who dwell there and they are:

1. Mechanus - Axis, The Clockwork Nirvana of Mechanus.
2. Arcadia - The Peaceable Kingdoms of Arcadia.
3. Heaven - The Seven Mounting Heavens of Celestia.
4. Bytopia - The Twin Paradises of Bytopia.
5. Elysium - Blessed fields of Elysium, sometimes referred to as Nirvana by good aligned - claiming this the true peace.
6. The Beastlands - The Wilderness of the Beastlands.
7. Arborea - The Olympain Glades of Arborea.
8. Ysgard - The Heroic Domains of Ysgard.
9. Limbo - The Maelstorm, The Ever-Changing Chaos of Limbo.
10. Pandemonium - The Windsept Depths of Pandemonium.
11. Abyss - The Infinite Layers of the Abyss.
12. Carceri - The Tarterian Depts of Carceri.
13. Hades - Abaddon, The Grey Wastes of Hades.
14. Gehenna - The Bleak Eternity of Gehenna.
15. The Nine Hells - Hell, The Nine of Hells of Baator.
16. Acheron - The Infernal Battlefield of Acheron.

Generation of Positive and Negative Energy

The Negative and Positive planes don’t actually exist as literal planes; rather, they are metaphysical concepts (also known Metaphysical Elements). While the so-called good planes—Arcadia, The Heavens, Bytopia, Elysium, The Beastlands, Arborea, and Ysgard—tend to produce positive energy, and the evil planes—Acheron, The Nine Hells, Gehenna, Hades, Carceri, Abyss, and Pandemonium—tend to generate negative energy, this isn’t absolute. Every plane contains both positive and negative energies to some extent - Some speculate they are affected by the other planes and the 'good' planes only generate positive energy and receive negative energy from their counterparts, the 'evil' planes..

Even if all life on the Prime Material Plane were to vanish and then reappear in less than a second, this would have almost no effect on the energy flow from these planes, as they generate more than enough to sustain countless realms. This, I believe, reflects the fundamental nature of metaphysical elements.

— Qusrur, a Mind Flayer in one of his little test-subjects

Demi Planes

These are smaller, personalized planes often tied to specific deities or powerful entities. The number of demiplanes is limitless.

History

The Celestial System as we know of today, was created with the onslaught of Corellon Larethien and Gruumsh in event called The Separation of the Planes, where Gruumsh, presumably was jealous of the order of Theras, therefore, beginning the war of Chaos, throwing the world into chaos, forever shutting and disconnecting the planes from the prime material plane. During this conflict, the Moons of Theras and the sun were heavily damaged, enabling the seperation to be done.