Is marriage an institution or a relationship? Here is "a" definition of institution from Wikipedia. Institutions are structures and mechanisms of social order and cooperation governing the behavior of a set of individuals. Institutions are identified with a social purpose and permanence, transcending individual human lives and intentions, and with the making and enforcing of rules governing cooperative human behavior. The term, institution, is commonly applied to customs and behavior patterns important to a society, as well as to particular formal organizations of government and public service. As structures and mechanisms of social order among humans, institutions are one of the principal objects of study in the social sciences, including sociology, political science and economics. Institutions are a central concern for law, the formal regime for political rule-making and enforcement. The creation and evolution of institutions is a primary topic for history. Regarding relationship, here is "a" definition or two. Also from Wikipedia An intimate relationship is a particularly close interpersonal relationship. It is a relationship in which the participants know or trust one another very well or are confidants of one another, or a relationship in which there is physical or emotional intimacy. An interpersonal relationship is a relatively long-term association between two or more people. This association may be based on emotions like love and liking, regular business interactions, or some other type of social commitment. Interpersonal relationships take place in a great variety of contexts, such as family, friends, marriage, acquaintances, work, clubs, neighborhoods, and churches. They may be regulated by law, custom, or mutual agreement, and are the basis of social groups and society as a whole. Although humans are fundamentally social creatures, interpersonal relationships are not always healthy. Examples of unhealthy relationships include abusive relationships and codependence. A relationship is normally viewed as a connection between two individuals, such as a romantic or intimate relationship, or a parent-child relationship. Individuals can also have relationships with groups of people, such as the relation between a pastor and his congregation, an uncle and a family, or a mayor and a town. Finally, groups or even nations may have relations with each other, though this is a much broader domain than that covered under the topic of interpersonal relationships. See such articles as international relations for more information on associations between groups. Most scholarly work on relationships focuses on romantic partners in pairs or dyads. These intimate relationships are, however, only a small subset of interpersonal relationships. All relationships involve some level of interdependence. People in a relationship tend to influence each other, share their thoughts and feelings, and engage in activities together. Because of this interdependence, anything that changes or impacts one member of the relationship will have some level of impact on the other member. The study of interpersonal relationships involves several branches of social science, including such disciplines as sociology, psychology, anthropology, and social work.