As students of sociology, we learn about social norms. Social norms are guidelines for expected behaviors, thus they set out our options for appropriate behavior. Bradley Wright’s blog post nicely describes a number of social norms operating in a college setting.
Not everyone follows the norms (deviance might be defined as not following the norm), challenging the social order. Note that the norms are guidelines for expected behaviors. They are the “should dos” and, sometimes the “must dos” of society. Norms can be loosely held, such as folkways, or tightly held, such as mores and taboos, those that are often built into the legal code.