From The Art and Popular Culture Encyclopedia
The term extended family has several distinct meanings. First, it is used synonymously with consanguineous family or joint family. Second, in societies dominated by the conjugal family or nuclear family, it is used to refer to kindred who does not belong to the conjugal family. Often there could be many generations living under the same roof, depending on the circumstances.
People living together as an extended family occasionally feel a greater security and belonging. This is an advantage of extended type of family because this family contains more people to serve as resources during crisis and provides more role models for behavior of values. The disadvantage of living in an extended type of family is shouldering more expenses for their basic needs.
Around the world
In many cultures, such as in those of many of the Southern Europeans, Asians, Middle Easterners, Africans, Latin Americans, and Pacific Islanders, extended families are the basic family unit. Cultures in which the extended family is common usually happen to be collectivistic cultures.
Australian Aborigines are another group for whom the concept of family extends well beyond the nuclear model. Aboriginal immediate families include aunts, uncles and a number of other relatives who would be considered "distant relations" in context of the nuclear family. Aboriginal families have strict social rules regarding who they can marry. Their family structure incorporates a shared responsibility for all tasks.Template:Citation needed
It refers to people related by blood or near age, in contrast to elementary/nuclear family and joint family, have married/unmarried offspring, married/unmarried siblings and may not have three generations living together- 6-10 members living in a house.
A big family is a family consisting of at least three generations living together. Usually the family is headed by the oldest man. More often than not, it consists of grand-parents, their sons and their son's families