Occlusion culling is a technique used in computer graphics to improve rendering efficiency by not drawing objects that are blocked from view. When a scene is rendered, the graphics engine determines which objects are visible to the camera. If an object is completely hidden behind another object, it can be skipped during the rendering process, saving computational resources. This method is particularly useful in complex scenes with many overlapping objects, as it reduces the number of polygons that need to be processed. By implementing occlusion culling, developers can create smoother and more responsive experiences in video games and simulations.