Here’s a simple, traditional Jain explanation.

• Madhya Lok (Middle World)

- The central region of the universe (Lokākāśa). - Beings with bodies (humans, animals, plants, many devas and nārakas in transit) are found here. - It contains concentric islands (dvīpas) and oceans (samudras). Only here can a soul practice right faith, right knowledge, right conduct and attain liberation. - Both Digambar and Shwetambar traditions accept Madhya Lok as the only realm where spiritual effort toward moksha is possible; minor differences exist in some measurements and sub-divisions, not in the core idea.

• Jambūdvīpa (Jambhu Dvip)

- The central “island/continent” of Madhya Lok. - Mount Meru (Sumeru) stands at its center; around it are regions like Bhārat Kṣetra, Airāvat Kṣetra and Mahāvideh Kṣetra. - Tirthankars appear in Jambūdvīpa; hence it is specially auspicious for dharma and liberation. - Both traditions agree on this structure; variations may occur in exact dimensions and counts of mountains/rivers, but not in the essential meaning.

To see clear, beginner-friendly explanations and diagrams, you can read:

• Jain geography overview
• Jambudweep (Jambūdvīpa) explained
• Diagrammatic view of the three worlds (Trilok)
• Jambudweep model at Hastinapur (for a visual grasp)