Educational technology is developed on the basis of audio-visual teaching method, personalized teaching method and improved experimental method. With the introduction of scientific and technological means and the influence of related theories (communication theory, system science theory, learning theory, etc.). ), forming an educational technology based on the design and evaluation of teaching process and the development and utilization of teaching media. Educational technology is a new branch of pedagogy, which constantly improves its guiding ideology and theoretical framework during the development of educational technology, and gradually separates from the category of teaching methods. The difference between it and other branches of education lies not in the purpose and task of this subject-in order to improve and obtain effective learning effect, but in its thoughts, means, methods and methodology of analyzing and solving educational and teaching problems. As D. ely said in the early 1970s, "The main goal in the field of educational technology is to promote and improve the quality of human learning. Because the task proposed by this goal is common to all branches of education, it cannot be put forward as the theoretical basis of a special field. The characteristics of educational technology, so it can be said that the reason for its existence lies in its philosophy and practical methods to achieve this goal. As the characteristics of educational technology, its methods can be demonstrated through three development models. In the past 50 years, it has developed this field. These three

Its model is: applying all kinds of learning resources; Emphasize personalized learning; The method of using the system. It is when these three modes are integrated into a kind of intelligent method and operation method to promote learning that the characteristics of educational technology are formed, thus laying a theoretical foundation in this field. From this discussion, we can clearly understand the basic idea, operation method and methodology of educational technology in analyzing and solving educational and teaching problems, as well as the nature and characteristics of the discipline. Therefore, we believe that educational technology is based on the ideas, principles and methods of system science theory, communication theory and learning theory to study and solve educational and teaching problems, and to explore the technical process of establishing and implementing learning mode and the theory and practice of media utilization.

As R.Cape said: "A basic goal in the field of educational technology is to promote and assist the application of well-known and proven methods in instructional design and teaching. Therefore, in theory, the core of educational technology research can be considered as the study of effective learning conditions, and technology can be used to improve teaching design and teaching. " However, because the development of educational technology is only a few decades old, it is a new field and discipline. Scholars and practitioners from different backgrounds put forward different definitions and definitions of educational technology from different angles, and all of them have achieved corresponding results in practice. Therefore, we don't need to judge them, we should learn from each other and allow them to develop independently.