Audiovisual production has, for a number of decades, used an increasing number of ever more sophisticated technologies to play 3D and 4D real and virtual content in long takes. Grouped under the term “3D video” these technologies (motion capture (Mocap), augmented reality (AR) and free viewpoint TV (FTV) and 3DTV) complement one another and are jointly incorporated into modern productions. This chapter deals with the fundamental principles of 3D videos and the techniques involved in this. This chapter presents an overview of the different periods of history which have marked the development and formalization of 3D. Notably, the chapter details the geometric principles related to central projection (pinhole cameras). It then examines aspects relating to the physiology of human vision before concluding, with a more taxonomic perspective, by proposing a classification of 3D visual approaches.