Sprite Atlas is a technical term that is extremely important in rendering and optimizing game graphics (technical art). An optimization feature that automatically packs multiple independent 2D images (sprites) into one huge connected texture at build time, dramatically reducing draw calls for 2D drawing and UI (uGUI).
Real-world analogy: Instead of holding dozens of small stickers separately and peeling them off and pasting them each time, you can arrange them into one "giant sticker sheet (atlas)" and carry them around, making it more efficient to paste them all at once
Every time a different image is displayed, we no longer instruct the GPU to ``switch the camera's film to the next image (texture binding)'' and instead convert it to an ultra-lightweight process that simply switches and displays ``the UV coordinates (crop range) of this range'' in one huge photo, completely eliminating the overhead of texture switching.
Figure: Infographic that clearly illustrates the basic processing flow and mechanism of Sprite Atlas in Japanese.
Detailed mechanism and operating principle
Create a "Sprite Atlas" asset, register all the icon images to be used in it, automatically connect them to one texture at build time, send them all at once to the GPU and draw them super fast with 1 draw call.