The document summarizes several theories of audience and media effects: 1) Audience Theory proposes that media producers target either mass or niche audiences and must understand their audience. 2) The Frankfurt School viewed audiences as passive, accepting media messages without question. 3) The Two Step Flow Theory posits that opinions flow from media to opinion leaders to the broader audience, making audiences more active. Opinion leaders influence others rather than the media directly influencing all. 4) Uses and Gratifications Theory sees audiences as active in choosing media to fulfill needs like diversion, relationships, identity and surveillance of useful information. Individuals consume media for different reasons.