Electrodynamics is a classical dynamic theory to study electromagnetic phenomena. This paper mainly studies the basic properties and motion law of electromagnetic field and the interaction between electromagnetic field and charged substances. Like all cognitive processes, human's understanding of electromagnetic motion forms is gradually deepening from special to general and from phenomenon to essence. People's understanding of electromagnetic phenomena is a process from special aspects such as static electricity, magnetostatics and quasi-steady current to general motion.

Learning electrodynamics should pay attention to the following points:

1. To learn physics electromagnetism well, it is recommended to read the electromagnetism part of "Fundamentals of Physics" translated by Professor Zhang Sanhui co-authored by Halid and resnick;

2. To learn math well, I recommend reading Wang Yongcheng who retired from Normal University.