loka, (Sanskrit: "world"; "realm"; "abode"; "dimension"; or "plane of existence") from loc, "to shine, be bright, visible." — the universe or any particular division of it. A dimension of manifest existence; cosmic region. Each loka reflects or involves a particular range of consciousness.
The most common division of the universe is the triloka, or three worlds (Bhuloka, Antarloka and Brahmaloka), each of which is divided into seven regions. Corresponds to any of the 14 worlds (visible and invisible) inhabited by living beings.
The division of lokas
Sometimes different “planes” or “realms” lokas are posited, which are corresponding “environments” for the different bodies: these are the bhûrloka (earth), bhuvarloka (the subtle planes or atmosphere), svarloka (the heavenly realm), maharloka, janarloka (these first five correspond to the panchakoshas — "five koshas"), and then there are the highest lokas, sometimes known as tapoloka, satyaloka, siddhaloka, and brahmaloka.
Scriptures offer several cosmological perspectives, most importantly sapta urdhvaloka (seven upper worlds) and sapta adholoka (seven lower worlds), which correspond to the 14 chakras and make up the "world-egg of God," the universe, called Brahmanda.
