Every person occupies a position in a social system.
The relationships among these positions make up the social structure . Social structure and positions affect people in a last three ways. We have role expectations about how occupants of positions will behave, e.g. we expect professors to behave in a certain way. Positions are associated with sets of relationships, which we call social networks. Each of us is woven into several networks, including those involving coworkers, family, and friends.