Overdraw is a technical term that is extremely important in rendering and optimizing game graphics (technical art). An explanation of the phenomenon where translucent objects etc. are drawn over and over again on the same screen pixel, causing the fill rate load on the GPU to exceed its limit and become unstable.
Real-world analogy: A wasteful oil painting where ``transparent paint'' is applied hundreds of times to the same spot on the canvas
Overdraw is ``the wasted work of overlapping transparent paint (transparent particles) one after another on the same spot on the canvas''. Each coat requires time to dry (GPU pixel calculations), but after 30 coats, artists keep painting the spot endlessly, wasting time (drawing processing time) even though the underlying image is barely visible (the alpha value is saturated). The smartest approach is to minimize overlap.
Illustration: Overdraw Infographic that clearly illustrates the basic processing flow and mechanism of (overdraw/overdraw) in Japanese.
Detailed mechanism and operating principle
Reduce the number of particles generated, trim the margins of the texture (completely transparent area) to cut polygons and cut unnecessary pixel calculations, or optimize to draw translucent at low resolution.