Short answer: They are four ways of looking at the same story, switched from the view control in Forge's top bar. Stage (the default) puts the running game itself on your editing canvas. Story Map shows the whole project as a flowchart of scenes. Script shows the story as text, one scene at a time. Split keeps the Stage on screen while a drawer holds Script or the Story Map beside it. Switching never loses your place - whatever you had selected in one view is where the next view picks up.
Switching views
The switch sits in the top bar, labeled Stage / Story Map / Script / Split. Click a label to swap the center of the workspace; the timeline, dock, episode bar, and scene strip around it stay put. The top bar also holds Theme (restyle the reading UI) and Menu (the title-screen editor) - those two are separate full-width views, so entering either one takes over the whole center and leaves Split.
Stage - the game is the canvas
Stage is where Forge opens. Instead of a preview window next to an editor, the running game is the editing surface: you click a line to edit it in the real textbox, drag characters on the real frame, and see every change land in the game as you make it.
Script - the story as text
Script shows each scene as editable text, with a scene list on the left. It comes with the help you'd expect from a serious text editor - suggestions as you type, hover explanations, renaming across the whole project, and problems flagged as you write. See How do I edit my story as text?.
Story Map - the whole story as a flowchart
Story Map draws the whole project as a flowchart: every scene is a card, cards run in story time, chapters are drawn as bands, and arrows show every route the story can take. It opens with scenes reading left to right and episodes as stacked rows, and two toggles - Episodes: rows or columns and Scenes: across or down - arrange it for the screen you have, remembered per project and per place you opened it. Filters, an ending-by-ending route isolate and an issue list turn it into the place you answer "where am I, and what is broken?" See What is the Story Map?.
Split - stage plus a drawer
Split shows the live Stage together with a tabbed drawer holding either the Story Map or Script, so you can study the map or write while watching the game respond. The drawer opens on the Story Map, arranged for the narrow space beside the Stage - scenes reading top to bottom, chapters as columns side by side - which you can change there like anywhere else; the Script tab sits next to it. Two layouts:
- Stacked (the default) - the Stage on top, the drawer below it.
- Side by side - the Stage on the left, the drawer on the right.
Toggle between them with the layout switch in the drawer's header. Drag the drawer's edge to resize it; Forge remembers the size you chose for each layout separately, and remembers your layout choice between sessions. Everything you can do on the Stage - editing lines, moving sprites - still works while the drawer is open.
Switching keeps your place
Moving between views is not a context switch. If you select an event in Script or a scene on the Story Map and then return to the Stage, the stage seeks to that exact moment. The playhead, your selection, and the rendered frame stay in agreement no matter which view you used to get there.