I do not like violent films with a lot of blood and gore but am a big fan of the films of Alfred Hitchcock. Hitchcock was rightly called the ‘master of suspense’ and in this brief interview he explains the difference with what he tried to do and what one sees in some other films.
He said that he wanted the audience to use their imaginations about what is going on rather than telling them and so he did not actually show the violence. For example, in the famous shower scene in Psycho, one does not actually see the victim being stabbed and blood spurting all over the place. One sees her screaming, one sees the assailant in silhouette making stabbing motions, one hears the screeching music rise to a crescendo, and one sees dark fluid representing blood swirling down the drain. All that is more than enough for the viewer to imagine what happened.