Pixel
The smallest visual unit in an electronic display or visual data file; a single "dot".
Most modern electronic displays are composed of a grid of pixels. Each pixel can be turned on or off, or - in the case of full-color displays - dimmed or made a specific color. In this way, pixels are individually controlled to cause the whole display to show information and graphics.
An important measure of an electronic display the number of pixels. More pixels allow the display to show more detail and more information. This is called "resolution", and is typically stated in terms of vertical and horizontal pixels (such as 240 x 320).
See: Resolution
Pixels can also be used to describe the smallest visual unit in a visual data file, such as a captured photograph or video clip.