It is a form of marriage in which one man marries more than one woman at a given time. It is of two types --- Sororal polygyny and non sororal polygyny
It is a type of marriage in which the wives are invariably the sisters. It is often called sororate.
It is a type of marriage in which the wives are not related as sisters.
It is the marriage of one woman with more than one man. It is less common than polygyny. It is of two types---- Fraternal Polyandry and non fraternal polyandry.
When several brothers share the same wife the practice can be called alelphic or fraternal polyandry. This practice of being mate, actual or potential to one's husband's brothers is called levirate. It is prevalent among Todas.
Non - fraternal polyandry:
In this type the husband need not have any close relationship prior to the marriage. The wife goes to spend some time with each husband. So long as a woman lives with one of her husbands; the others have no claim over her.
It is a form of marriage in which one man marries one woman .It is the most common and acceptable form of marriage.
In many societies individuals are permitted to marry again often on the death of the first spouse or after divorce but they cannot have more than one spouse at one and the same time.
In this remarriage is not allowed.
It means the marriage of two or more women with two or more men. Here the husbands are common husbands and wives are common wives. Children are regarded as the children of the entire group as a whole.