Final answer:
Marriage is a complex and variable institution globally, traditionally between two individuals but also allowing for polygamous arrangements in certain cultures. It provides a framework for offspring rearing and socioeconomic stability, and adapts to societal changes and different cultural values.
Step-by-step explanation:
Marriage is a socially recognized union that holds varied meanings and practices across different cultures and societies. While traditionally involving two people, the conception of marriage varies greatly: monogamous relationships are standard in postindustrial societies and cultures with high mobility, but polygamous relationships can be predominant in cultures where children contribute to the economy, such as in small-scale farming societies. In the context of cultural relativism, it's essential to understand that marriage can be a legal, social, or religious contract, and the definition may include unions beyond two individuals, reflecting the society's norms and values. Societies implement rules of endogamy and exogamy to guide marital practices and maintain social structures. Changes in society, like shifts in gender roles or economic conditions, can result in adaptations in marriage practices, such as the move towards consensual unions in places like Iceland. Anthropologists and sociologists find that marriage is crucial for the creation of alliances, production and nurturing of offspring, and providing socioeconomic stability. The diverse forms of marriage observed across the world illustrate the adaptability of this institution to social change and cultural values.