In Jainism, a Tirthankar (a ford-maker) is not chosen by people or by a council. It is believed that a soul becomes a Tirthankar when it has purified itself completely and achieved kevala jnana (absolute, infinite knowledge) along with perfect faith and conduct. Here’s the simple idea:

• The soul renounces worldly life and conquers all inner passions (like anger, pride, deceit, greed) and outer temptations.
• The soul attains kevala jnana and omniscience, i.e., perfect knowledge of all things.
• After attaining this highest realization, the soul teaches the Jain Dharma to help others cross the worldly cycle of birth and death.
• A Tirthankar then becomes a religious teacher and establishes a path (tirth) for others to cross over to liberation (moksha).

Key points, including tradition-specific notes:

• Time and cosmic cycles: In the current half-cycle (ara) of time, there are 24 Tirthankaras. The first is often counted as Rishabhanatha, and the last is Mahavira. The sequence and details are described differently in Digambara and Shwetambara traditions, but both agree on the basic idea of a Tirthankar as a fully enlightened teacher who revives the Dharma.
• Role and function: Each Tirthankar creates a ford (tirth) and establishes the Jain teaching during his era, enabling others to practice right faith, right knowledge, and right conduct.
• Gender and order: Both major Jain sects recognize 24 Tirthankaras in this cycle; there are nuanced differences in biographical details and temple traditions, but the overarching concept remains the same.

If you want, I can summarize the specific list of the 24 Tirthankaras and give a brief note on how Digambara and Shwetambara traditions differ in their biographical accounts.