Supersampling is a technique used in computer graphics to improve image quality by reducing aliasing, which can cause jagged edges in images. It works by rendering the image at a higher resolution than the display resolution, then downsampling it to the desired size. This process helps to create smoother edges and more detailed visuals. In practice, supersampling can enhance the appearance of video games and animations, making them look more realistic. While it can significantly improve image quality, it also requires more processing power, which may affect performance on some systems.