Marriage is an institution in which interpersonal relationships (usually intimate and sexual) are acknowledged by the state, by religious authority, or both. It is often viewed as a contract. Civil marriage is the legal concept of marriage as a governmental institution, in accordance with marriage laws of the jurisdiction. If recognized by the state, by the religion(s) to which the parties belong or by society in general, the act of marriage changes the personal and social status of the individuals who enter into it.
People marry for many reasons, but usually one or more of the following: legal, social, and economic stability; the formation of a family unit; procreation and the education and nurturing of children; legitimizing sexual relations; public declaration of love; or to obtain citizenship." (www.wikipedia.org)