The book details the CD device and its player. It describes how and from what the CD is made, in what form the information is stored on it and how high reliability of storage is achieved. Particular attention is paid to the discussion of factors affecting the sound of the sound signal, issues of CD quality and equipment. The possible disadvantages of both are described. The book describes the preparation of a professional phonogram and the methods of subjective assessment of the recording quality. The abundance of unique information, visual material, as well as the methodology and simplicity of presentation make this book interesting for both a specialist and an unprepared reader.