This document defines personal media as private individuals using media technologies to create and share personal expressions through digital networks, such as mobile phones, email, and photo sharing services. It contrasts personal media with mass media, which provides generally accessible information. The document then discusses the history of personal media and how digitalization has made media more multi-functional, with the same technologies serving both personal and mass communication purposes. It also reviews some models for conceptualizing personal versus mass media, including in terms of interactional roles and network structures.