On input devices such as scanners, the smallest point the device can detect. Also known as a pixel.
On an output device, such as an imagesetter, film recorder, or plotter, the smallest point that the laser can image. These spots are what form the image, and the number of spots in a unit of linear distance (such as an inch) is what determines the output device's resolution. Although resolution of output devices is often measured in dots per inch, and spots are often referred to as dots, the use of this latter term is technically incorrect; the word spot is preferred as a means of distinguishing between the "dots" generated by the output device and halftone dots. Many spots are used to make up a halftone dot (which, when made up of spots, is known as a halftone cell).