Editing involves selecting and combining shots into sequences to create a narrative. Early films had little editing as shots were continuous with no variation. Robert Paul pioneered basic editing techniques by cutting between shots to show continuity. George Melies further advanced editing by discovering visual effects and using double exposure. Modern digital editing allows nonlinear editing on computers, making the process quicker and easier than splicing film. Effective editing engages audiences through techniques like pacing, motivation, and reaction shots.