24 Tirthankar tap means the austerities (tapas) done by the 24 Tirthankaras of Jainism as they renounced the world and uplifted others on the path to Moksha. Tapas here signifies self-discipline, control over passions, and intense spiritual practices that purify the soul.

Key points you can understand simply:

• Each Tirthankar is said to have practiced severe tapas before attaining omniscience (Kevala Jnana) and guiding others.
• Tapas in Jainism is both external (bahya) and internal (abhyantara): external fasting, restraint, and renunciation; internal meditation, moral discipline, right faith, and non-violence.
• The general pattern across the 24 Tirthankaras is renunciation, strict self-control, meditation, and preaching after attaining enlightenment.

Different Jain traditions (Digambara and Śvetāmbara) sometimes describe or emphasize aspects of tapas a bit differently, but the core idea remains: purified conduct and inner discipline lead to omniscience and liberation.

If you’d like, tell me a specific Tirthankar you’re curious about (for example, Mahavira or Adinath), and I can share the typical tapas associated with that Tirthankar in a simple, tradition-faithful way.