Class refers to a system that groups or ranks individuals based on wealth–most simply by three strata–upper class, middle class, and lower class. Except at the very extreme ends of the spectrum (very wealthy or very poor), class often is invisible. Yet, class is still an important factor in shaping who we are and what kinds of opportunities we’re afforded. American history is permeated with the narrative of the “American Dream,” though critics contend that upward mobility is increasingly difficult. Media creates messages about class through the way characters speak, where they live, what they wear, and what they drive. See topic overview PDF for more.