in human context, a family is a group of people affiliated by consanguinity, affinity, or co-residence. In most societies it is the principal institution for the socialization of children. Extended from the human "family unit" by biological-cultural affinity, marriage, economy, culture, tradition, honour, and friendship are concepts of family that are physical and metaphorical, or that grow increasingly inclusive extending to community, village, city, region, nationhood, global village and humanism. A family group consisting of a father, mother and their children is called a nuclear family. This term can be contrasted with an extended family.
There are also concepts of family that break with tradition within particular societies, or those that are transplanted via migration to flourish or else cease within their new societies. As a unit of socialization and a basic institution key to the structure of society, the family is the object of analysis for sociologists of the family. Genealogy is a field which aims to trace family lineages through history. In science, the term "family" has come to be used as a means to classify groups of objects as being closely and exclusively related. In the study of animals it has been found that many species form groups that have similarities to human "family"—often called "packs."
- Mother: a female parent
- Father: a male parent
- Son: a male child of the parent(s)
- Daughter: a female child of the parent(s)
- Brother: a male child of the same parent(s)
- Sister: a female child of the same parent(s)
- Grandfather: father of a father or mother
- Grandmother: mother of a mother or father
- Cousins: two people that share the same grandparent(s)