What are the differences in image quality when comparing cameras based on their ISO performance?

When comparing cameras based on their ISO performance, the differences in image quality can be seen in the amount of noise or graininess present in the photos. Cameras with better ISO performance will produce clearer and sharper images with less noise, especially in low light conditions. Cameras with lower ISO settings typically produce higher quality images with less noise, while cameras with higher ISO settings may introduce more noise and reduce image quality.