Stage directions are written instructions in a script that guide actors and directors on how to perform a scene. They indicate movements, positions, and actions of characters, as well as details about the setting, lighting, and sound. These directions help create the intended atmosphere and ensure that the performance aligns with the playwright's vision. Typically found in italics or brackets, stage directions can also describe emotions or reactions, providing context for the actors. They are essential for conveying the playwright's intentions and enhancing the overall storytelling in a theater production.