Step 1: Fix caste as a closed system:
Caste status is inherited at birth, cannot normally be changed, and is reinforced by endogamy and traditional occupational restrictions.
Step 2: Fix class as an open system:
Class status depends on economic factors like income and occupation, which can rise or fall within a single lifetime, making class boundaries far more fluid than caste boundaries.
Final Answer:
The key difference is mobility and basis: caste is a fixed, birth-based, ritually-ranked closed system, while class is an economically-based, relatively open system that permits social mobility.