Diwali in Jainism centers on Mahavira’s Nirvana (moksha) at Pawapuri. The day is observed as the Nirvana Day of Mahavira. The next day is traditionally associated with Gautam Swami attaining Keval Jnana (omniscience), and the Jain year is said to begin after Diwali with Pratipada (the first day) of the new year. Digambar and Śvetāmbara communities both commemorate Mahavira’s Nirvana on Diwali, with only minor calendar differences in some year calculations. The overall meaning remains the same: illumination of true knowledge and renunciation, with fasting and reflection typical during the period. You can read more here