There are three main sociological perspectives. These are structural functionalism, conflict, and symbolic interactionism. Each has a different view on social institutions.
Structural functionalism holds that a society is essentially like a living organism. That is, a society is made up of various parts that are all necessary to the overall functioning of that society. Each part of society, like each organ in a human body, has some role to play in the overall health of society. In this view, social institutions are some of the most important organs. They shape people and their interactions and allow society to remain stable. As an example of this, the family provides a controlled outlet for sexual desire and a way to ensure that children are cared for and socialized.
Conflict theory holds that groups in society are in conflict and competition with one another. Once one group wins in a conflict, it uses its dominance to set up rules and traditions that will help it stay in power. In this view, social institutions are set up to further the interests of the groups that have won in the conflict. For example, a conflict theorist might argue that families are the result of men winning the conflict with women. They therefore set up a family structure in which women have often been placed in a subordinate position.
Symbolic interactionism has less to say about social institutions. It is based on the idea that individual perceptions of reality, and not social institutions, are what matter. A symbolic interactionist might say that the meaning of the family depends on how each individual perceives the family. The institution itself, then, does not have that much meaning.