This document provides an introduction to media studies. It defines media as collective communication outlets used to deliver information, including television, music, newspapers, the internet and advertising. Media studies is described as the discipline that analyzes content, history and effects of mass media. The document outlines the importance of media literacy in making sense of increasing media messages. It then gives a brief history of media development and an overview of four eras in the evolution of media theories, from early mass society theories to current cultural criticism approaches. Key theories from each era are also summarized.