DPI refers to “dots per inch” and is a form of measurement in graphic design. It is important to understand that this form of measurement has no effect of image size OR quality on a computer screen. The measurement governing images on a screen is PPI or “pixels per inch”. Rather, DPI sets the size an image will print out to on a piece of paper. For example, two images on the screen both 300 x 100 pixels set to different DPIs (say 72dpi and 720dpi) will both appear the exact same size and exact same quality and will still have the same total number of pixels (30,000).
However, once these images are printed to paper, the 72dpi image will show up larger and less detailed while the 720dpi image will be smaller and more detailed because more ink is being laid onto the paper in a smaller spacing. If the difference is still confusing, please refer to this article!
