Douga (動画) roughly translates to moving image and is sometimes translated into "video". Douga are the cleaned up/polished versions of genga sketches. During the animation process genga ( key frame drawings) are made and then in the next step are sent to the douga-men. There the drawings get cleaned up and retraced onto clean white paper with the sketch number in the top right corner. Additional in between frames are made at this point as well. This is usually done by younger or new animators. These douga sketches are what finally makes it onto the screen. If it is a computer animated show the douga sketches are scanned and then digitally colored. If it's a pre-2001 show they were copied onto acetate and then painted to make Cels.