Stage

The top-level container is the Stage class that displays a window on the display device. It contains the Scene class, and the content of the scene is represented as a hierarchical scene graph of nodes. Figure 1 shows a simple scene graph example. In this graph, the root node is the Pane class, which manages the layout of nodes inside it. The pane contains three control nodes: Button, Label, and TextField classes.

Ushio Inoue, GUI Testing for Introductory Object-Oriented Programming Exercises, 2019, p. 3