In Jain cosmology, the hell realms (naraka) are described using extremely large time units, mainly:

• Palyopama
• Sāgaropama

These are vast cosmic time measures used to express the unimaginably long lifespan and suffering of hell beings. Their duration is far beyond ordinary human years.

In simple terms:

• Palyopama = an enormous, hard-to-imagine unit of time
• Sāgaropama = even larger, like countless palyopamas

Jain texts use these units because the time spent in naraka is so vast that normal years are not enough to describe it.

If you want, I can also explain the Jain time units from samaya to sāgaropama in a simple chart.