text: JPEG files achieve a smaller file size by compressing the image in a way that retains detail which matters most, while discarding details deemed to be less visually impactful. JPEG does this by taking advantage of the fact that the human eye notices slight differences in brightness more than slight differences in color. The amount of compression achieved is therefore highly dependent on the image content; images with high noise levels or lots of detail will not be as easily compressed, whereas images with smooth skies and little texture will compress very well.