This document provides summaries of several media theories and concepts: 1) Adorno's hypodermic model which views media as very powerful in influencing audiences. 2) Blumler and Ketz's users and gratifications model which sees media use as fulfilling personal relationships and diversion needs. 3) Hall's encoding/decoding model where media producers encode messages and audiences can decode them in dominant, negotiated, or oppositional ways based on their own experiences and values.