An acronym meaning dots per inch.
In display, a measure of the sharpness (that is, the density of illuminated points) on the screen. The dots per inch for a given picture resolution will differ based on the overall screen size since the same number of pixels are being spread out over a different space.
In printing, the usual measure of printed image quality on the paper. The average personal computer printer today provides 300 dpi or 600 dpi. Choosing the higher print quality usually reduces the speed of printing each page.