Pixel Art

In digital imaging, a pixel, pel,[1] or picture element[2] is a physical point in a raster image, or the smallest addressable element in an all points addressable display device; so it is the smallest controllable element of a picture represented on the screen. 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 (or relatively limited) computer, console, graphing calculator and mobile phone video games are mostly pixel art. Pixel art was very often used in older computer and console video games. With the increasing use of 3D graphics in games, pixel art lost some of its use. Despite that, this is still a very active professional/amateur area, since mobile phones and other portable devices still have low resolution and therefore require skillful use of space and memory. Sometimes pixel art is used for advertising too. Modern pixel art has been seen as a reaction to the 3D graphics industry by amateur game/graphic hobbyists.[4][5] Many retro enthusiasts often choose to mimic the style of the past. Some view the pixel art revival as restoring the golden age of second and third generation consoles, where it is argued graphics were more aesthetically pleasing. Pixel art still remains popular and has been used in social networking virtual worlds such as Citypixel and Habbo, as well as among hand-held devices such as the Nintendo DS, Nintendo 3DS, PSP, PS Vita and Cellphones, and in modern indie games such as Hotline Miami and FTL: Faster Than Light. Pixel art is also used in textures for Minecraft.

Tutorial:

PISKEL
http://www.piskelapp.com/
With this website you are able to create sprites for games or backgrounds.