Dots Per Inch / Pixels Per Inch definition

Dots per inch or pixels per inch are the units of measurement used by the output device quality of print.   It relates to the number of pixels or dots that a printer is capable of printing in each inch. For example, a print at 72dpi will have 5184 dots on one square inch or the paper (72 x 72).  It may also relate to the pixels or the dots per inch of an image that is scanned.