Step 1: Define caste.
Caste is a closed social group into which a person is born, and it fixes that person's status, traditional occupation, and marriage circle (through endogamy) for life, arranged in a ranked order based on notions of ritual purity and pollution.
Step 2: Explain education and legal change as factors.
The spread of modern education has opened new careers based on merit rather than birth, letting people move out of their traditional caste occupation, while laws such as the abolition of untouchability and reservation policy have legally attacked caste based discrimination and improved access for lower castes.
Step 3: Explain economic and urban factors.
Industrialization and urban migration mix people of different castes together in factories, offices, and city neighbourhoods, weakening the strict separation that caste needs to survive, and new non-farm occupations mean income is less tied to traditional caste work.
Step 4: Explain political and cultural factors.
Democratic politics, where every adult has one vote regardless of caste, has forced caste groups to organise for political bargaining rather than only for ritual status, and social reform movements plus mass media have spread ideas of equality that challenge old caste hierarchy.
Final Answer:
Caste is a birth based, ranked social group; education, law, industrial and urban growth, and democratic politics together have weakened its rigidity and reshaped it over time.