Film editing involves cutting different footage sections together to form a sequence. Early films used longer 1-minute shots due to technology limitations, while modern films typically use 2-3 second shots. Sergei Eisenstein developed the concept of montage, juxtaposing shots to imply meanings and progress the story. Editing techniques like match cuts, cross cuts, and jump cuts manipulate time and space for narrative purposes, with the "Hollywood method" establishing spatial and temporal continuity through techniques like 180-degree lines and shot-reverse-shot.