In Jainism, the universe is called "Lok" (or "Loka"). According to Jain cosmology, Lok is divided into three main parts:

1. Urdhva Loka (Upper World): This is the abode of the heavenly beings (devas).
2. Madhya Loka (Middle World): This is where humans, animals, and many other beings reside. Our Earth is a part of Madhya Loka.
3. Adho Loka (Lower World): This is the realm of the hellish beings (narakis).

The Lok is described as having a fixed shape, often compared to a man standing with his legs apart and arms resting on his waist (known as the "cosmic man" or "lokapurusha"). The universe, according to Jainism, is eternal and uncreated. It is finite in space but infinite in time; there is no place outside the Lok where souls can exist.

Outside of Lok is "Alok," which is pure void and cannot sustain any form of life or matter. According to Jain teachings, only the Lok contains all living beings, karma, time, and matter.

So, the Lok in Jainism is one—singular—but divided into these three major regions.