In the context of Jainism, "Aras" refers to one of the units used to measure extremely long periods of time, especially in describing the Jain concept of cosmic cycles (Kālacakra).

The Jain time cycle (Kālacakra) is divided into two halves: Utsarpini (ascending half-cycle) and Avasarpini (descending half-cycle). Each half-cycle is further divided into six Aras (also spelled as "āras" or "arasas"), which are immense periods, each with its own characteristics concerning happiness, age, height, and moral values.

The six Aras in each half-cycle are:

1. Sukhama-sukhama (Utmost happiness)
2. Sukhama (Happiness)
3. Sukhama-dukhamā (Happiness with some sorrow)
4. Dukhamā-sukhama (Sorrow with some happiness)
5. Dukhamā (Sorrow)
6. Dukhamā-dukhamā (Utmost sorrow)

Each Ara lasts for millions of years, and humanity's moral and physical conditions change with each Ara. Currently, according to Jain cosmology, we are in the fifth Ara (Dukhamā), which is marked by increasing sorrow and spiritual decline.

In summary: Aras are divisions of time in Jain cosmology, representing different ages or epochs within the cosmic cycle.