A pixel;short for picture element, using the common abbreviation “pix” for “pictures” is a single point in a graphic image. Each such information element is not really a dot, nor a square, but an abstract sample. With care, pixels in an image can be reproduced at any size without the appearance of visible dots or squares; but in many contexts, they are reproduced as dots or squares and can be visibly distinct when not fine enough. The intensity of each pixel is variable; in color systems, each pixel has typically three or four dimensions of variability such as red, green, and blue, or cyan, magenta, yellow, and black.
Pixel art is a form of digital art, created through the use of raster graphics software, where images are edited on the pixel level. Graphics in most old computer and video games, graphing calculator games, and many mobile phone games are mostly pixel art. (wikipedia.org)