1、Development history refers to the development of history, what happened in the middle of the development process, the reasons for the emergence of these things and what role they played in the development of history, etc. Development is a process of progress and change of things from birth, is the constant renewal of things. It is a continuous process of change. There are both quantitative and qualitative changes.

2、Connotation of development.

Development includes changes in both physical and mental aspects of an individual.

The course of development includes the whole life of an individual. Development exists regardless of age.

Development involves multiple areas. For example, the individual's body, brain, thinking, imagination, emotions, etc., are all within the scope of development.

Development refers not only to the process of forward advancement, but also to the changes of decline and demise.