Often a wallpaper looks like an edited picture of the reality or it is reality. Wallpapers you see often from; Cars Footbal Games Cities etc. It can be from everything of course from animals till the universe. Instead of backgrounds that are often more abstract images that are generated entirely by a computer. Also for example in a powerpoint presentation we use backgrounds most of the time instead of wallpapers. So the conclusion is that most of the time wallpapers are used for example, your phone or your tablet and backgrounds we use more for PowerPoint presentations and photo albums etc.