Biyasana and Upvās are both types of bahya tap (external tapa) related to food-discipline.

• Biyasana – taking food only twice a day at fixed times, with discipline.
• Upvās (Upvas) – full fast for the day (no food; water as per the vow/maryādā).

Both are counted under the external tapas (bahya tap) among the 12 types of tapa in Jain Dharma.

You can read a simple list of Jain fasts here