Jainism reveres 24 Tirthankaras in the present half-cycle of cosmic time.
A Tirthankara is a Jain spiritual teacher who discovers and teaches the path across samsara, the cycle of birth and death, toward liberation. The word is often explained as “ford-maker,” because a Tirthankara establishes a crossing over the otherwise difficult river of rebirth.
Jain cosmology divides time into repeating ascending and descending cycles. Each half-cycle is said to produce exactly 24 Tirthankaras, so the number 24 refers specifically to the current cosmic period rather than to every Tirthankara who has ever existed. Jain tradition holds that infinitely many Tirthankaras have appeared across past, present, and future cycles.
Rishabhanatha is the first of the present 24, while Mahavira is the twenty-fourth and last. Mahavira lived in the sixth century BCE and is the most historically documented Tirthankara, while Parshvanatha, the twenty-third, is also widely treated as a historical figure. The number is sometimes confused with 24 Jain symbols or with the 24 elders of Revelation, but those are separate associations.