In Jain Dharma, fasting is generally done as tapas to reduce attachment to the body and increase आत्मशुद्धि. The main kinds are:

1. Upvas

Total fasting — no food or drink, usually for a full day or longer.

1. Ayambil

One simple meal in the day, without taste-enhancing items like oil, ghee, milk, curd, sugar, fruits, or spices.

1. Ekasana

Eating only once in a day, in one sitting.

1. Biyasana

Eating twice in a day, but still with restraint and discipline.

1. Chauvihar / Tivihar / Avadhir

These are forms of limiting food and water intake according to Jain practice, especially with time restrictions.

1. Partial fasts / Vrat-based restraint

Such as eating less, avoiding certain foods, or observing food discipline on specific days.

1. Varsitap

A well-known austerity in which one alternates between one day of fasting and one day of eating, for about a year.

1. Masakshaman

A monthly fast, usually for about 30 days, done with great discipline.

1. Attham / Aaththam

Fasting for 3 days, traditionally observed on sacred occasions.

1. Bela, Tela, Athai

Fasts of 2, 3, or 8 consecutive days.

In Jain tradition, the most important thing is not only the type of fasting, but also bhavna, samyam, and ahimsa in practice.

If you want, I can also give these in a simple table or explain the difference between Upvas, Ekasana, and Ayambil.