For many people, their immediate family is more than just their spouse, parents, and children. Grandparents, aunts, uncles, and cousins are generally considered part of the immediate family, too. While defining who is considered an immediate family member may be distinct for different purposes, generally immediate family members are defined as those who are closest and therefore most affected by the family's success or failure.

Immediate family is often accompanied by an extended family, which is a wider group of relations such as distant relatives, stepparents, step-siblings, in-laws, and other people who may not always enjoy the same degree of closeness that exists within the immediate family. These extended family members may also have an influence in matters such as inheritance.

The role of extended family can be especially important in situations such as illness, death, or financial hardship. For many families, extended family members can provide emotional and financial support, serve as trustees of family trust funds, look after the finances and provide gifts to grandchildren, or serve as a source of advice and counsel. Some families also have extended family members who provide care for the elderly or ill family members.

Myriad other factors can contribute to determining the composition of the immediate and extended family. Legal statuses, such as adoption and guardianship, can have an impact, as can religious and cultural factors. For example, in some Asian communities, every adult in the family may be considered as a source of advice and assistance to other family members, including those from outside the immediate family.

Although the terms "immediate family" and "extended family" are often used interchangeably, they each have their distinct advantages. Understanding the difference between these two types of families can help a family unit to better serve the needs of the individual members and continue to preserve the family bond.