Both genre and tone are used effectively within films to create a theme altogether. However, while both of these are used to do this, they are completely different from one another. For example, tone is used to give off an atmosphere to the audience, such as when a film wants to make the audience distraught, then the film would impose a depressing atmosphere, weather that would be through character emotions or even the background music. On the other hand, genre is the whole theme of a film and what type of film it is. So, if you are watching a film that is about a murderer, then that film would be classified as a crime film, but someone may suggest that it is a horror film because they felt scared during the film through the feelings that the murderer gave.