In the Jain Dharma Chakra (the wheel shown on the palm of the Jain symbol):

• The wheel itself = Dharma (right path / right conduct).
• It has 24 spokes.
• These 24 spokes represent the 24 Tirthankaras of the current time‑cycle.
• Meaning:

Just as spokes support a wheel, the teachings of the 24 Tirthankaras support and guide the soul on the path to moksha.

Both Digambar and Shwetambar traditions accept this same basic meaning: 24 spokes = 24 Tirthankaras, and the wheel = continuous practice of right faith, right knowledge, and right conduct.

You can read a simple explanation of the Jain symbol and dharma chakra here