What was the nature of social classification in the Early Vedic Age? How did it differ from that of the Later Vedic Age?

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.