What term describes a household comprised of one man, one woman, and their children if any?

The term that best describes a household comprised of one man, one woman, and their children, if any, is "nuclear family." This concept is fundamental in sociology and refers specifically to a family unit that includes two parents (traditionally a male and a female) and their biological or adopted children living together.

This structure emphasizes the immediate family members as the primary social unit and differentiates it from other types of family arrangements, such as extended families, which include other relatives like grandparents, aunts, or uncles. A single-parent family focuses on households headed by one parent, while a blended family includes children from previous relationships along with new partners, making them distinct from the nuclear family. Therefore, the nuclear family is the most accurate description for the scenario provided in the question.