Texture atlasing combines multiple small textures into a single large texture to reduce the number of texture switches during rendering. Every time the GPU switches to a different texture, it incurs overhead -- state changes are one of the most expensive operations in the rendering pipeline. By packing many textures into one atlas and using UV coordinates to reference the correct sub-region, the renderer can draw multiple objects with a single draw call and one texture bind. This is especially impactful for 2D games with hundreds of sprites, UI systems with many icons, and 3D games with lots of small decals or props. The packing algorithms try to minimize wasted space while keeping related textures together. Sprite sheets for 2D animation are a form of texture atlasing that has been used since the earliest days of game graphics.