A nuclear family is a family group consisting of parents and their children (one or more), typically living in one home residence. The term "nuclear" refers to all members of the family being part of the same core rather than directly to atomic weapons. The traditional definition of a nuclear family is a family unit that includes two married parents of opposite genders and their biological or adopted children living in the same residence. However, the term "nuclear family" can mean several things in todays society. Here are some characteristics of a nuclear family:

• Consists of a pair of adults and their socially recognized children.
• Typically, but not always, the adults in a nuclear family are married.
• Children in a nuclear family may be the couple’s biological or adopted offspring.
• There can be any number of children in the family, and one or both parents may work outside the home.
• Within a nuclear family, there can be parents who may identify as LGBTQ+ .
• Ideally, within a nuclear family, there are shared values, responsibilities, unconditional love, healthy attachment patterns, and an environment that supports growth and learning.

It is important to note that anthropological research has illuminated so much variability of this form that it is safer to assume that what is universal is a “nuclear family complex” in which the roles of husband, wife, mother, father, son, daughter, brother, and sister are embodied by people whose biological relationships are not necessarily those specified in a given definition of the nuclear family.