What is the term for a family structure consisting of a married couple and their unmarried children living together?

The term for a family structure consisting of a married couple and their unmarried children living together is known as a nuclear family. This concept describes the basic family unit centered around two parents and their biological or adopted children. The nuclear family is often contrasted with other family forms, such as extended families, which may include additional relatives like grandparents, aunts, uncles, or cousins living together or maintaining close relationships.

In contrast, a single-parent family comprises one parent raising one or more children, which does not fit the description of a married couple. A blended family refers to a family where at least one partner in a couple has children from a previous relationship, merging different family units. Thus, the nuclear family is the ideal term to define the structure comprising two parents and their dependent children living under one roof.