To form a sprite, you must first define it and then create a formal data
structure in memory. You define a sprite by specifying its characteristics:

   *  On-screen width of up to 16 pixels.
   *  Unlimited height.
   *  Any shape.
   *  A combination of three colors, plus transparent.
   *  Any position on the screen.

 screen position       sprite color 
 size of sprites       designing a sprite 
 shape of sprites      building the data structure