Answer

In Jain Dharma, these fasting practices are generally understood as:

• One day fast — Upvas: no food for one full day.
• Ekasana — eating only once in one sitting during the day.
• Beasana / Biyasana — eating twice in the day, each time in one sitting.
• Two days continuous fast — Bela / Chhath.
• Three days continuous fast — Tela / Attham.

Explanation

Your line seems to be asking about the names of tapasya:

• 1 day fast = Upvas
• 2 days fast = Bela / Chhath
• 3 days fast = Tela / Attham

Ekasana is not the same as a full fast. In Ekasana, one eats only once, in one sitting, usually within proper Jain dietary discipline.

Spiritual Understanding

The purpose of fasting in Jain Dharma is not only physical restraint, but mainly:

• control over desires,
• reduction of attachment to taste and food,
• inner purification,
• focus on samayik, pratikraman, swadhyay, and bhavna.

Takeaway

Upvas means one full-day fast, Bela/Chhath means two continuous fasts, and Tela/Attham means three continuous fasts.