Trailokya

Trailokya (Skt., त्रैलोक्य trailokya; Pali, tiloka; Standard Tibetan: khams-gsum (Wylie)) has been translated as "three worlds," "three spheres," "three planes of existence," "three realms" and "three regions." These three worlds are identified in Hindu and early Buddhist texts, have counterparts in Brahmanical sources and are elaborated upon by more recent Theosophical theory.

Buddhist cosmology

In Buddhism, the three worlds refer the following karmic rebirth destinations:

Kāmaloka:
world of desire, typified by base desires, populated by hell beings, preta, animals, ghosts, humans and lower demi-gods.
Rūpaloka:
world of form, predominately free of baser desires, populated by jhana-dwelling gods, possible rebirth destination for those well practiced in jhanic absorption.
Arūpaloka:
world of formlessness, noncorporal realm populated with four heavens, possible rebirth destination for practitioners of the four formlessness stages.

Bhuvanatraya is the brahmanical fourfold division of worlds. These systems can be juxtaposed in the following manner:

Brahmanical Worlds		Buddhist Worlds
1. Bhur, earth.		1. World of desire, Kamadhatu or Kamaloka.
2. Bhuvah, heaven, firmament.		2. World of form, Rupadhatu.
3. Swar, atmosphere, the sky.	}	3. The formless world, Arupadhatu.
4. Mahar, eternal luminous essence.	}	3. The formless world, Arupadhatu.

Each of the brahmanical worlds represents a post-mortem state.

According to Blavatsky's posthumously published Theosophical Glossary (1892):

Kamaloka (or kamadhatu) is the world of Mara. Kamaloka has, like every other world, its seven divisions, the lowest of which begins on earth or invisibly in its atmosphere; the six others ascend gradually, the highest being the abode of those who have died owing to accident, or suicide in a fit of temporary insanity, or were otherwise victims of external forces. It is a place where all those who have died before the end of the term allotted to them, and whose higher principles do not, therefore, go at once into Devachanic state—sleep a dreamless sweet sleep of oblivion, at the termination of which they are either reborn immediately, or pass gradually into the Devachanic state. This is that which medieval and modern Kabalists call the world of astral light, and the "world of shells".

Rupaloka (or rupadhatu) is the celestial world of "form" (rupa), or what we call "Devachan." With the uninitiated Brahmans, Chinese and other Buddhists, the Rupadhatu is divided into eighteen Brahma or Devalokas; the life of a soul therein lasts from half a Yuga up to 16,000 Yugas or Kalpas, and the height of the "Shades" is from half a Yojana up to 16,000 Yojanas (where a Yojana measures from five and a half to ten miles). Esoteric Philosophy teaches that though for the Egos for the time being, everything or everyone preserves its form (as in a dream), yet as Rupadhatu is a purely mental world, and a state, the Egos themselves have no form outside their own consciousness. Esotericism divides this world into seven Dhyanas, "regions", or states of contemplation, which are not localities but mental representations of these.

Arupaloka (or arupadhatu) is a world that is again divided into seven Dhyanas, still more abstract and formless, for this "World" is without any form or desire whatever. It is the highest world of the post-mortem Trailokya; and as it is the abode of those who are almost ready for Nirvana, and is, in fact, the very threshold of the Nirvanic state, it stands to reason that in Anupadhatu (or Arupavachara) there can be neither form nor sensation, nor any feeling connected with our three dimensional Universe.[4]

According to Rudolf Steiner's Theosophy book, the three worlds are the Physical World, the Soul World, and the Spiritland.