In the Early Vedic Age, society was divided into four varnas based on occupation—Brahmanas (priests), Kshatriyas (warriors), Vaishyas (traders/farmers), and Shudras (labourers). This system was flexible, and movement between varnas was possible.
However, in the Later Vedic Age, the varna system became rigid and hereditary. A clear social hierarchy emerged: Brahmanas and Kshatriyas held the highest positions, Vaishyas occupied the middle tier, and Shudras were at the bottom, expected to serve the upper classes. Inter-varna marriages and mobility were no longer allowed.