Kinship terminology refers to the system of terms used in a particular culture to classify and address relatives. These terms are not merely labels but reflect and reinforce the social organization, rights, and obligations within a society. Kinship systems are fundamental to understanding social structure, descent, marriage patterns, and inheritance.

Anthropologists distinguish between two broad categories: descriptive and classificatory systems. Descriptive terms assign a unique term to each specific relative (e.g., 'mother's brother' is distinct from 'father's brother'). Classificatory terms, on the other hand, group several different relatives under the same term (e.g., a single term might be used for 'mother's brother' and 'father's brother,' or even for 'mother' and 'mother's sister').

Lewis Henry Morgan identified six major kinship terminology systems: Eskimo, Hawaiian, Iroquois, Sudanese, Crow, and Omaha. The Eskimo system, common in Western societies, emphasizes the nuclear family by giving unique terms to immediate family members while lumping collateral relatives (e.g., all cousins are 'cousins'). The Hawaiian system is highly classificatory, using a single term for all relatives of the same sex and generation. The Iroquois system distinguishes between parallel and cross-cousins, reflecting unilineal descent. Each system provides insights into how a society defines family, descent, and social roles, highlighting the cultural diversity in structuring human relationships beyond biological ties.