The family is a social institution found in about half of human societies in the world today. The U. S. Census Bureau defines the "family" as people living together who are linked by birth, marriage, or adoption. A family that includes parents, children and other kin is called a nuclear family. A family composed of one or two parents and their children is called an extended family.

people living together who are linked by birth, marriage, or adoption.

Explanation:

Families remain the most essential social institution in the world. Since a family is a group of individuals living together and linked by blood, marriage or through adoption with emotional connections, some other forms of family are being suggested.

Advocates of LGBT will also include other non traditional forms in these definition.

The family is recognized for it fully contributes to key social functions:

The addition of new members - like the offspring, and this way they lead to further resizing of families

The physical care of members - where times require it, often someone will care and watch for the health of the loved ones.

The socialization of children. an essential process that is needed for further adults that they will become, and needed for a healthy biosocial development

The social control of members, which means teaching children the accepted values of right and wrong, and encouraging values as a discipline, hard work, etc.

Families also are important in producing and Consuming Goods and Services. Household account for key economic activity.