Dynamic Batching is a technical term that is extremely important in game graphics rendering and optimization (technical art). An automatic optimization function that reduces draw calls by grouping vertex information of small moving objects (such as bullets or simple coins) in real time on the CPU every frame.
Real-world analogy: Instead of sending each customer in a separate taxi, dynamic carpooling allows people heading in the same direction to ride together on a bus
Dynamic batching is "an ad hoc delivery system in which multiple small packages (small meshes) bound for the same destination (material) are hurriedly sent out on one truck (one draw call) just before departure (every frame).'' However, since the CPU performs the work of calculating and assembling luggage on the spot every frame, there is a trade-off in that if the luggage is too heavy or too large, the computation of packaging (CPU load) will be heavier than dividing the trucks.
Figure: Infographic that clearly illustrates the basic processing flow and mechanism of Dynamic Batching in Japanese notation
Detailed mechanism and operating principle
Enable "Dynamic Batching" in Project Settings, and the CPU instantly combines the vertices of small objects that use the same material in memory, and then draws them in one go.