This document discusses several theories related to media languages, codes, conventions, and semiotics. It explains that media languages include symbols and structures that cue audience understanding. Codes and conventions are familiar techniques used to communicate ideas or impressions, like camera angles, music, and character dress. Semiotics is the study of signs and their cultural meanings. Theories discussed include Roland Barthes' work on semiotics in media, Claude Levi-Strauss' concept of binary oppositions in narratives, and Andrew Goodwin's characteristics of music videos.