Kinship terminology refers to the system of terms used in a society to classify relatives and define their relationships. It is not merely a reflection of biological ties but a cultural construct that encodes social organization, rights, obligations, and behavioral expectations. The specific terms used are determined by a set of underlying principles or 'determinants' that anthropologists have identified.

1. Generation: This is a universal determinant, distinguishing relatives based on their generational distance from Ego (the individual whose kinship is being traced). For example, terms differentiate parents from children, and grandparents from parents. This principle establishes a vertical hierarchy in kinship.

2. Gender/Sex: Also a universal determinant, it differentiates relatives based on their biological sex. For instance, 'mother' is distinct from 'father,' and 'brother' from 'sister.' This distinction often reflects different social roles and expectations associated with gender.

3. Affinity vs. Consanguinity: This principle distinguishes between blood relatives (consanguines) and relatives by marriage (affines). For example, 'mother' (consanguine) is distinct from 'mother-in-law' (affine). This distinction is crucial for understanding marriage alliances and the formation of new kin ties.

4. Collaterality: This determinant distinguishes between lineal relatives (those in a direct line of descent, like parents, children, grandparents) and collateral relatives (those related through a common ancestor but not in a direct line, like siblings, aunts, uncles, cousins). For example, 'father' is distinct from 'father's brother' (uncle). Some systems, like Hawaiian, merge these, while others, like Eskimo, maintain a clear distinction.

5. Bifurcation: This principle distinguishes between relatives on the mother's side (matrilateral) and relatives on the father's side (patrilateral). For example, 'mother's brother' is distinct from 'father's brother.' This is particularly important in societies with unilineal descent systems, where one side of the family is emphasized over the other.

6. Relative Age: In many societies, terms differentiate relatives based on whether they are older or younger than Ego or another reference point. For example, 'elder brother' vs. 'younger brother' is common in many Asian kinship systems, reflecting hierarchical relationships and respect.

7. Sex of Ego (Speaker's Sex): In some kinship systems, the term used for a relative depends on the sex of the person speaking (Ego). For instance, a man might use one term for his sister's child, while a woman uses a different term for her sister's child, reflecting different roles and relationships for male and female Egos.

8. Sex of Connecting Relative: The term for a relative might depend on the sex of the person through whom the relationship is traced. For example, 'mother's brother's child' might be terminologically distinguished from 'father's sister's child,' especially in systems that practice cross-cousin marriage.

9. Social Distance/Closeness: Beyond genealogical distance, kinship terms can also reflect perceived social closeness or distance, which may be influenced by factors like residence, interaction frequency, or shared responsibilities.

10. Descent Rules: The rules of descent (e.g., patrilineal, matrilineal, bilateral) profoundly shape kinship terminology. Unilineal systems tend to merge relatives on the non-descent side, while bilateral systems often have more classificatory terms that group many relatives under a single term.

These determinants combine in various ways to produce the six major kinship terminology systems identified by anthropologists (Eskimo, Hawaiian, Iroquois, Crow, Omaha, Sudanese). Each system reflects the unique social structure, marriage patterns, and cultural values of the society in which it is found, providing a linguistic map of social relationships and obligations.