1. political history: study political systems, political events and politicians in various periods, such as the rise and fall of ancient empires and the evolution of modern democratic systems.
2. Economic history: Study the economic system, economic development and economic crisis in different periods, such as the influence of industrial revolution on the world economy and the economic structure of feudal society in China.
3. Cultural history: the study of cultural phenomena, cultural exchanges and cultural changes in different periods, such as the influence of the Renaissance on European culture and the inheritance and innovation of China's ancient culture.
4. Social history: study the social structure, social problems and social changes in different periods, such as the formation and collapse of slave society and the change of women's status.
5. Military history: study the military organization, war strategy and war influence in different periods, such as the influence of World War II on the world pattern and the military technology of ancient wars.
6. Diplomatic history: Study international relations, foreign policies and diplomatic events in different periods, such as the influence of the Cold War on world peace and the ancient tributary system in China.
7. Religious history: study religious beliefs, rituals and religious influences in different periods, such as the spread and influence of Christianity and the development of Buddhism in China.
8. Urban history: study urban planning, urban construction and urban development in various periods, such as the construction and management of ancient Roman cities and the problems in the process of modern urbanization.