A marriage is a relationship between or among individuals, usually recognized by civil authority and/or bound by the religious beliefs of the participants. The fact that marriage often has the dual nature of a binding legal contract plus a moral promise, can make it difficult to characterize.In one form or another, marriage is found in virtually every society. The very oldest records that refer to it speak of it as an established custom. Despite attempts by anthropologists to trace its origin , evidence is lacking.
In Western societies, marriage has traditionally been understood as a monogamous union, while in other parts of the world polygamy has been a common form of marriage. Usually this has taken the form of polygyny but a very few societies have permitted polyandry . Precise definitions vary historically and between and within cultures: modern understanding emphasizes the legitimacy of sexual relations in marriage, yet the universal and unique attribute of marriage is the creation of affinal ties . Traditionally, societies encourage one to marry "out" far enough to strengthen the ties, but "close" enough so that the in-laws are "one of us" or "our kind".
