What does low-sensitivity image quality mean in photography? What about high-sensitivity image quality?

To put it simply, it is the image quality at low sensitivity and the image quality at high sensitivity

What people say:

The higher the sensitivity, the better the picture. The greater the exposure.

Without the use of flash, the weaker the ambient light, the higher the ISO required to shoot, because the shutter speed can be relatively increased to prevent hand shake caused by low shutter speed. The photo is blurry and the dynamic subject cannot be frozen in the photo due to the low shutter speed. Another effect of sensitivity is that the higher the sensitivity, the more noise there will be in the photo.