300 ppi VS 72 ppi
Resolution represents what physical size will the image display as, and how much detail will be visible. 300 ppi and 72 ppi are both resolutions that represent pixels per inch. Those aren't normal low and high resolution variants. What you have there, is two images that are identical, except that the low PPI thinks it's going to spread those 1280x768 pixels thinly across a large area and making it look more bigger, while the high PPI one thinks it's going to concentrate those 1280x768 pixels in a high quality print on one particular area of focus. However both of the resolutions have the same data. Both of these resolutions mainly make a difference when you are outputting the image. If you’re printing you want to have at least 300 pixels for every inch of size you plan on printing. For screens you don’t want more than 72 pixels for every inch you expect to see. But when you open the image in an editor, the resolution displayed in the s...