(1) World.
(2) Plane. A division of the Universe. Such as our Earth is also a Lok - called Bhoo Lok or Prithvi Lok. In general the Universe is divided in three Lok - (1) Bhoo - the Earth; (2) Bhuvah - the region between the Earth and the Heaven where the good souls go to live after their death; and (3) Swaha - the Heaven where Indra rules. Together they are pronounced "Bhoor Bhuvah Swaha". This combination is added to Gaayatree Mantra and is called Vyaahriti

Another popular division, which is not mentioned in real scriptures, is Earth, Heaven and Hell. Hell is situated below the Earth and Heaven above.

In some books, the Universe is divided in 8 Lok. According to Ved there are 8 Lok - (1) Bhoo (the Earth), (2) Bhuvah, (3) Swar, (4) Mahar, (5) Jav, (6) Tapo, (7) Satya - in the ascending order - Satya being the highest. Narak is the Hell and is situated below the Earth. According to Puraan, there are several Hell - Paataal, Rasaatal, Talaatal (but only seven names, as the names of seven lower Lok, are found - (1) Mahaatal, (2) Sutal, (3) Atal, (4) Tal, (5) Talaatal, (6) Sutal, and (7) Rasaatal.).

There is no unanimity about the description of these. Some Puraan describe 14 Lok -  6 Lok above Prithvi and 7 Lok below Prithvi -
(7) Bhoor Lok (Prithvi Lok), (6) Bhuvar Lok, (5) Swarg Lok, (4) Mahar Lok, (3) Jan Lok, (2) Tapo Lok, and (1) Satya Lok.
The lower Lok are - (8) Mahaatal, (9) Sutal, (10) Atal, (11) Tal, (12) Talaatal, (13) Sutal, and (17) Rasaatal.

Ved say - "For the 7 planes,

There are 7 Rishi - Atri, Bhrigu, Kutsa, Vashishth, Gautam, Kashyap and Angiras
There are 7 Chhand - Gaayatree, Ushnik, Anushtup, Brihatee, Pankti, Trishtup, and Jagatee
There are 7 Devtaa - Agni, Vaayu, Ark, Vaageesh, Varun, Indra and Vishwedev

In Padm Puraan, 2/12, Maatali tells about Lok to Yayaati - "Maatali said - "Devtaa's Lok are like feelings. Feelings have various forms, their number may go up to millions, but for Punyavaan people their number is only 28, which are located one above the other and are very large in size."