Nuclear family consists of –
FAMILY

The family is a primary unit in all societies.
It is a group of biological related individuals living together and eating from a kitchen.

Type of families

Nuclear family (elementary family) → Consists of the married couple and their children while they are still regarded as dependents.
Joint family extended family → Consists of number of married couple and their children who live together in same household. All of men are related by blood and women of the household are their wives, unmarried girls and widows of the family kinsmen.

Three generation family → This tends to be household where there are representatives of three generations.
Husband, wife and son
Husband, wife and dependent children
Husband and wife only
Father mother husband and wife