Some countries do not recognize locally performed religious marriage on its own, and require a separate civil marriage for official purposes.
Conversely, civil marriage does not exist in some countries governed by a religious legal system, such as Saudi Arabia, where marriages contracted abroad might not be recognized if they were contracted contrary to Saudi interpretations of Islamic religious law.
These trends coincide with the broader human rights movement.
Marriage can be recognized by a state, an organization, a religious authority, a tribal group, a local community, or peers. When a marriage is performed and carried out by a government institution in accordance with the marriage laws of the jurisdiction, without religious content, it is a civil marriage.
In developed parts of the world, there has been a general trend towards ensuring equal rights within marriage for women and legally recognizing the marriages of interfaith, interracial, and same-sex couples.
Religious marriage recognizes and creates the rights and obligations intrinsic to matrimony before that religion.
Religious marriage is known variously as sacramental marriage in Catholicism, nikah in Islam, nissuin in Judaism, and various other names in other faith traditions, each with their own constraints as to what constitutes, and who can enter into, a valid religious marriage.
Since the late twentieth century, major social changes in Western countries have led to changes in the demographics of marriage, with the age of first marriage increasing, fewer people marrying, and more couples choosing to cohabit rather than marry.
For example, the number of marriages in Europe decreased by 30% from 1975 to 2005.
The anthropological handbook Notes and Queries (1951) defined marriage as "a union between a man and a woman such that children born to the woman are the recognized legitimate offspring of both partners." In recognition of a practice by the Nuer people of Sudan allowing women to act as a husband in certain circumstances (the ghost marriage), Kathleen Gough suggested modifying this to "a woman and one or more other persons." In an analysis of marriage among the Nayar, a polyandrous society in India, Gough found that the group lacked a husband role in the conventional sense; that unitary role in the west was divided between a non-resident "social father" of the woman's children, and her lovers who were the actual procreators.