Global Illumination is a rendering technique used in computer graphics to simulate how light interacts with surfaces in a scene. Unlike basic lighting methods that only consider direct light from a source, Global Illumination accounts for both direct and indirect light. This means it captures how light bounces off surfaces, creating more realistic images with soft shadows and natural color blending. By using Global Illumination, artists and designers can create lifelike environments in video games, movies, and architectural visualizations. Techniques like Ray Tracing and Radiosity are often employed to achieve this effect, enhancing the overall visual quality and immersion of the scene.