Dots per inch
Also called: DPI or dots per inch
DPI (dots per inch) is the number of dots per inch that make up a graphic image. The more dots per inch, the sharper the image. This unit of resolution is primarily used to indicate the sharpness of printed materials.
A common resolution for print is 300 DPI. The resolution of most monitors has traditionally been 72 DPI, although this is changing with the advent of retina and 4K screens, among other things. As a general rule, though, print requires sharper/detailed files than display on a website or monitor.
Difference between dots and pixels
A dot is not the same as a pixel. A dot is a physical dot that can be printed by a printer, displayed on a monitor or observed by a scanner. However, the graphics files that these devices use or produce may consist of more or fewer pixels. For monitors and other displays, sharpness is often expressed in pixels per inch.
In printing, for example, a file is reduced or enlarged to the desired print size if necessary. The DPI of the printer or printing press determines how sharp a print can theoretically become. The desired size (in inches or centimeters) and sharpness (in DPI) together determine how many pixels a supplied digital file should consist of. The more pixels available in a file, the smaller they will become on the final product and thus the more detail the print will contain.
