'world', denotes the 3 spheres of existence comprising the whole universe, i.e.

• (1) the sensuous world (kāma-loka), or the world of the 5 senses;
• (2) the fine-material world (rūpa-loka), corresponding to the 4 fine-material absorptions (s. jhāna 1-4);
• (3) the immaterial world (arūpa-loka), corresponding to the 4 immaterial absorptions (s. jhāna, 5-8).

The sensuous world comprises

• the hells (niraya),
• the animal kingdom (tiracchāna-yoni),
• the ghost-realm (peta-loka),
• the demon world (asura-nikāya),
• the human world (manussa-loka) and
• the 6 lower celestial worlds (s. deva I).

In the fine-material world (s. deva II) still exist the abilities of seeing and hearing, which, together with the other sense abilities, are temporarily suspended in the 4 absorptions. In the immaterial world (s. deva III) there is no materiality whatsoever, only the four mental groups (s. khandha) exist there.

Though the term loka is not applied in the Suttas to those 3 worlds, but only the term bhava, 'existence' (e.g. M. 43), there is no doubt that the teaching about the 3 worlds belongs to the earliest, i.e. sutta-period, of the Buddhist scriptures, as many relevant passages show.