Textbooks, also known as textbooks, are teaching books that are written according to curriculum standards and systematically reflect the subject content. Textbooks are the concretization of curriculum standards, which are different from ordinary books. They are usually divided into volumes, units or chapters according to the academic year or semester. It is mainly composed of content, text, exercises, experiments, charts, notes and appendices, and the text is the main part of the textbook. With the development of science and technology and the modernization of teaching methods, the carriers of teaching content are also diversified.