Hitchcock explains about CUTTING

On its most fundamental level, film editing is the art, technique, and practice of assembling shots into a coherent sequence. The job of an editor is not simply to mechanically put pieces of a film together, cut off film slates, or edit dialogue scenes. A film editor must creatively work with the layers of images, story, dialogue, music, pacing, as well as the actors' performances to effectively "re-imagine" and even rewrite the film to craft a cohesive whole. Editors usually play a dynamic role in the making of a film. Sometimes, auteurist film directors edit their own films,