In Jainism, the universe (loka) is eternal and without a creator. It is made of two fundamental substances: jiva (souls) and ajiva (matter, including time, space, etc.). The universe is infinite in extent and is organized into three main regions:

• Urdhva-loka (above): heavenly realms where beings enjoy pleasures; at the top there are liberated souls called siddhas who reside in Siddha-loka.
• Madhya-loka (middle): the human realm and other life-forms (animals, birds, insects, plants) where beings experience karma and have the possibility of salvation.
• Adho-loka (below): the various hells where beings undergo karmic retribution.

Key ideas to keep in mind:

• There is no fixed deity creator; natural laws of karma govern all beings.
• The universe is boundless in space but finite in time in each cycle of time, which follows repeating cosmic ages.
• Time is cyclical, consisting of rising and falling cosmic ages (utsarpini and avasarpini) with many Tirthankaras appearing in different cycles to guide souls.

In short, Jain cosmology presents a self-contained, eternal cosmos divided into upper, middle, and lower regions, populated by countless sentient beings, all moving under the law of karma toward liberation.