What is "dots per inch"

n. (context graphic design typography English) The measure of a number of pixels per inch used in a graphic or supported by a digital display device, used to specify type or image resolution.

Monitors do not have dots, but do have pixels. The closely related concept for monitors and images is pixels per inch or PPI.

Old CRT type video displays were almost universally rated in dot pitch, which refers to the spacing between the sub-pixel red, green and blue dots which made up the pixels themselves. Monitor manufacturers used the term "dot trio pitch", the measurement of the distance between the centers of adjacent groups of three dots/rectangles/squares on the CRT screen. Monitors commonly used dot pitches of 0.39, 0.33, 0.32, 0.29, 0.27, 0.25, or .

LCD monitors have a trio of sub pixels, which are more easily measured.