The document defines codes and conventions used to interpret visual and cultural symbols. It explains that codes are visual, audio or technical elements that imply meaning based on what audiences have learned. Conventions are recurring elements that group together to form genres. Codes have both a denotative literal meaning and connotative symbolic meaning. The document provides examples of visual codes like facial expressions and location, and technical codes like camera angles and music. It includes links to example movie trailers to analyze codes and conventions.