Tap (austerity) in Jainism is practiced to purify the soul and progress on the path to liberation. It is broadly categorized into two main kinds, with further examples under each. There are also minor variations in how Digambar and Śvetāmbar traditions describe practices.

1) Bahir-tap (external/physical austerities)

• Fasting (upavasa) and extended fasts: restricting or eliminating eating for spiritual purposes.
• Lugging the body through difficult practices: standing or sitting in uncomfortable postures for long periods, or performing bodily restraints.
• Severe weather hardship: enduring cold, heat, or other harsh conditions as a discipline.
• Sallekhana (voluntary end-of-life fasting): a conscious, voluntary practice toward the end of life with the aim of shedding karmas and attaining liberation. Note: the perception and use of sallekhana differ among Digambara and Śvetāmara traditions.

2) Antar-tap (internal/mental-spiritual austerities)

• Mindful speech and truthfulness: speaking carefully, avoiding lies, harsh words, or useless talk; practicing controlled, truthful speech.
• Non-attachment and restraint of desires: diminishing attachment to worldly objects, sense-control, and reduction of cravings.
• Inner meditation and recollection: practicing samayik (equanimity period), mirroring attention, and deep contemplation of karmic results.
• Non-violence in thought and intention: cultivating sincere compassion, avoiding ill-will, and purifying intentions.
• Controlling anger, pride, greed, and deceit: actively observing and reducing these mental vices.
• Study, reflection, and vows: regular study of Jain scriptures, reflection on dharma, and adherence to core vows (non-violence, truth, non-stealing, celibacy, non-possessiveness).

Notes on tradition differences

• Digambar and Śvetāmbar communities sometimes emphasize different emphasis or phrasing for certain practices, especially around what constitutes acceptable bodily asceticism and the interpretation of sallekhana.
• In both traditions, the spirit of tapas is to purify the soul, reduce karmic bondage, and advance toward kevalajñana (omniscience).

If you’d like, I can outline specific tapas mentioned in a particular Jain text (e.g., a Digambar or Śvetāmbar source) and provide a concise arth (meaning) for each, or explain how tapas is practiced in daily Jain life.