This document introduces the key concepts and theories related to understanding new media. It begins by discussing Marshall McLuhan and Friedrich Kittler's views that media play a central role in shaping humanity and history. It then examines different terms used to describe new media - digital media, online media, and new media - and argues that "new media" is the most appropriate term as it encompasses technological, connectivity, and novelty aspects without prioritizing any single attribute. The document concludes by outlining debates around the relationship between media/technology and society, and whether media determine society or vice versa.