Family and marriage may at first seem to be familiar topics. Families exist in all societies and they are part of what makes us human. However, societies around the world demonstrate tremendous variation in cultural understandings of family and marriage. Ideas about how people are related to each other, what kind of marriage would be ideal, when people should have children, who should care for children, and many other family related matters differ cross-culturally. While the function of families is to fulfill basic human needs such as providing for children, defining parental roles, regulating sexuality, and passing property and knowledge between generations, there are many variations or patterns of family life that can meet these needs. This chapter introduces some of the more common patterns of family life found around the world. It is important to remember that within any cultural framework variation does occur. Some variations on the standard pattern fall within what would be culturally considered the “range of acceptable alternatives.” Other family forms are not entirely accepted, but would still be recognized by most members of the community as reasonable.