This document discusses the history and theories of visual communication. It describes some of the earliest forms of visual communication dating back 50,000 years in the form of cave paintings and pictographs. It then outlines different symbol systems for communication including iconic symbols that are easy to learn, letter symbols that are more difficult, and linear written communication. The document also discusses how picture communication was once seen as primitive but may be more effective than other forms. It introduces theories of semiotics related to signifiers and signifieds, and Gestalt theory which focuses on the relationship between parts and the whole in a design.