Hi Guitta, very short, non-technical explanation: different from usual shaders which often aim at (photo-)realistic results, cell shaders produce cartoon-/comic strip-like output, i.e. images with reduced colour palettes, stark outlines and contrasts etc. Imagine creating a Vue scene, and render the image with a cell shader--you'll have a perfect background for a comic book or graphic novel. Hope this helps, -Sascha.rb