Final answer:
The presence of a stepparent or stepchild signifies a blended household, which is when partners with children from previous relationships form a new family.
Step-by-step explanation:
The presence of a stepparent or stepchild indicates a blended household. A blended family is one where one or both partners have children from previous relationships but have joined together to form a new, combined family structure. This is different from a nuclear family, which traditionally consists of a married couple and their biological or adopted children, and from an extended family, which includes relatives beyond the immediate family unit such as grandparents, aunts, and uncles.