The caste system in India is a complex and ancient form of social stratification, traditionally rooted in the concept of jati (birth group) and varna (fourfold hierarchical division). While its rigidities have been challenged by modernization and legal reforms, its characteristics have historically shaped Indian society:

1. Hierarchy: The most defining feature is its hierarchical structure. Society is divided into a graded order of castes, with Brahmins (priests and scholars) at the top, followed by Kshatriyas (warriors and rulers), Vaishyas (merchants and farmers), and Shudras (laborers and service providers). Below these four varnas were the Dalits (formerly 'untouchables'), who were considered outside the system and subjected to severe discrimination.

2. Endogamy: Marriage is strictly confined within one's own caste or sub-caste (jati). Inter-caste marriages were traditionally forbidden and often met with severe social ostracism or violence.

3. Hereditary Occupation: Traditionally, each caste was associated with a specific occupation, which was passed down from generation to generation. This limited social mobility and reinforced the division of labor based on birth.

4. Purity and Pollution: A core concept of the caste system is the idea of ritual purity and pollution. Higher castes were considered ritually pure, while lower castes, particularly Dalits, were deemed impure due to their occupations (e.g., handling dead animals, cleaning waste). This concept dictated social interactions, food sharing, and physical contact.

5. Restricted Social Interaction: Rules governed commensality (eating together) and social intercourse between different castes. Sharing food or water with lower castes was often prohibited for higher castes, reinforcing social distance.

6. Ascribed Status: An individual's status in the caste system is determined by birth and cannot be changed through personal achievement or effort. This ascribed status dictates one's social standing, opportunities, and life chances.

7. Segmental Division: Society is divided into numerous small, self-contained groups (jatis), each with its own customs, rules, and social mechanisms for enforcing them. While varnas are broad categories, the jati is the practical unit of the caste system.

8. Localised Nature: The specific hierarchy and customs of castes can vary significantly from one region to another, making it a localized and dynamic system rather than a uniform national structure.

Despite legal prohibitions against caste discrimination and the impact of urbanization, education, and economic changes, caste identity and its associated social inequalities continue to influence various aspects of Indian society, particularly in rural areas and in political mobilization.