Jain cosmology divides the universe (loka) into three broad realms:

• Urdhva Loka (Upper World): the heavenly realms where Devas (gods) reside. There are many Deva-lokas (often described as 16 major heavens in some lists) and advanced abodes above them. At the very top is Siddhashila, the realm of liberated souls. In Jain sources, these upper realms are part of the karmic world but are not permanent homes for moksha. You can read more about the Deva-lokas and Siddhashila in Jain cosmology discussions.

• Madhya Loka (Middle World): this is the human realm. It centers on Jambudvipa (the central continent) with Mount Meru at its spiritual center, surrounded by oceans and other continents. This is the realm where humans live and where liberation is possible. For a compact description of Madhya Loka and Jambudvipa, see the cosmology overview.

• Adho Loka (Lower World): the seven Naraka (hells) where beings experience suffering according to their karma. These are layered downward; descent corresponds to increasing suffering until karmic exhaustion leads to rebirth in a higher realm. A concise outline of the lower realms is available in Jain cosmology resources.

Notes:

• Some texts enumerate the upper worlds in more detail (for example, seven Deva-lokas or a sequence of Kalpas and Anuttara abodes). The core idea, however, remains: Upper World (heavens), Middle World (humans and other beings on Jambudvipa), Lower World (the seven hells).
• Siddhashila is the realm of liberated souls at the very top of the cosmos and represents moksha beyond further rebirths.

If you’d like, I can break down the exact names sometimes given for the 14 rajlok or the 7 Narakas, with the traditional terms used in Digambara vs. Śvetāmbara texts.