Historical materials refer to things that can be used as a basis for studying or discussing history. Generally speaking, historical materials are divided into primary materials and secondary materials. The former refers to the historical materials that are close to or directly generated from the time when history occurred, which can be used as the historical basis more directly, while the latter refers to the research and interpretation made by later generations using first-hand historical materials, but the boundary between the two is often not clear (for example, Historical Records can hardly be said to be first-hand or second-hand historical materials). Generally speaking, the historical materials in Chinese mainly refer to the first-hand historical materials.