Primary, secondary and tertiary kins

Primary kins:
Every individual who belong to a nuclear family finds his primary kins within the family. There are 8 primary kins- husband-wife, father-son, mother-son, father-daughter, mother-daughter, younger brother-elder brother, younger sister-elder sister and brother-sister.
Secondary kins:
Outside the nuclear family the individual can have 33 types of secondary relatives. For example mother's brother, brother's wife, sister's husband, father's brother.
Tertiary kins:
Tertiary kins refer to the secondary kins of our primary kins.For example wife's brother's son, sister's husband's brother and so on. There are 151 types of tertiary kins.