Filmmakers use plot diagrams for an overview of a story's basic structure. It shows the progression of the plot as a shark fin-shaped graph rising up to the climax, such as the hero defeating the main villain, and then falling. Scriptwriters can then place the scenes and individual shots from the more detailed script along this graph, helping to determine when a film's intensity should reach its maximum.
Since ancient times, the vast majority of successful stories in any medium have followed a similar structure: first a presentation of characters and setting, followed by the introduction of a conflict, its escalation, its resolution, and finally a denoument where the aftermath is explored. The escalation up to the climax, the rising part of the plot diagram, is usually longer than the falling part. More complex structures involve various subplots, each with their own progression up to their resolution, usually before the main plot resolves.
Typical Hollywood scriptwriting strictly follows this classic formula, with pace increasing the closer the movie gets to the high point in the diagram, which should be the most powerful scene. Many famous movies have arc plots, or classic plots, where the same typical basic components appear in the same order along the plot progression.