Monogamy is the condition of having a single marriage partner at any time. The qualification of "at any time" implies that if one of the partners dies, the survivor may remarry and this will not be counted as a breach of the monogamous rule.
While monogamy is virtually universal in Western countries, there are many other parts of the world where polygamy is accepted as part of the culture. Polygamy is the state of having more than one spouse at the same time. In the civil law of some jurisdictions, this may be termed bigamy (from the Latin, bi, meaning two.) The Christian ideal of marriage visualizes a lifelong monogamous union of husband and wife.
The reverse of polygamy, polyandry, where the wife has more than one husband, is exceedingly rare in modern times.
Other religions may permit polygamy. In Old Testament times, it was normal for a man to marry his brother's widow, due the fact that women had no rights in that culture outside of marriage.
The Qu'ran has directives with regard to marriage,permission for polygamy and divorce, and inheritance. The Qu'ran allows a man the right to marry more than one wife at a time, and to repudiate a wife through divorce. Wives may own property and have economic independence. However, in the case of divorce, the wife retains all her property.
Hinduism permits polygamy, although it was recently forbidden in civil law. The members of ruling families have always maintained large harems of wives and concubines; many of the wealthier men of all classes were polygamous. The ideal of marriage in Hinduism is given by Rama and Sita; The divine incarnation, Lord Rama is the perfect example who has one word, one arrow, one wife.