This selective glossary refers to basic terms used in the various handbooks offered in this kit. It provides explanations on terms in the lexical field of media techniques and educational techniques. Additional elements of analysis have been drawn from the most usually used terms in current media and communication theories. These theories are called here “critical positions” because they are seen only in their reference to the media, without attendant value judgments or in-depth reference to their authors. The glossary is not exhaustive and every user is encouraged to complete it. The definitions suggested are propositions, which every user is encouraged to modify, to elaborate upon and to fit to his or her specific needs. The terms in italics refer to complementary notions in the glossary.