Marriage is a governmentally, socially, or religiously recognized interpersonal relationship, usually intimate and sexual, and often created as a contract. The most frequently occurring form of marriage unites a man and a woman as husband and wife. Other forms of marriage also exist; for example, polygamy, in which a person takes more than one spouse, is common in many societies. Beginning in 2001, the legal concept of marriage has been expanded to include same-sex marriage in some jurisdictions.

The reasons people marry vary widely, but usually include one or more of the following: the public declaration of love; the formation of a family unit; legitimizing sexual relations and procreation; legal, social and economic stability; and the education and nurturing of children.

A marriage can be declared by a wedding ceremony, which may be performed either by a religious officiator or through a similar government-sanctioned secular officiator. The act of marriage often creates obligations between the individuals involved, and in many societies, their extended families. Marriages are perpetual agreements with legal consequences, terminated only by the death of one party or by formal dissolution processes such as divorce and annulment.