In JavaFX, the Scene class is used to represent the visual elements of a JavaFX application, including the layout, graphics, and user interface components. A scene is attached to a Stage object, which is a top-level container for the user interface of an application.

Here's an example of how to create and use a Scene in a JavaFX application:

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

public class MyJavaFXApp extends Application {

    @Override
    public void start(Stage primaryStage) {
        // Create a button and add it to a StackPane layout
        Button button = new Button("Click me!");
        StackPane layout = new StackPane(button);
        
        // Create a Scene object with the layout and set it on the stage
        Scene scene = new Scene(layout, 300, 200);
        primaryStage.setScene(scene);

        // Show the stage
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}

In this example, we create a simple Scene with a single Button component in a StackPane layout. The StackPane layout centers the button within the scene. We then set the Scene on the Stage using the setScene() method, and display the stage by calling the show() method.

The Scene class provides a number of methods for managing the visual elements of a JavaFX application. You can set the background color of the scene, add or remove nodes from the scene graph, and manipulate the layout of nodes using various layout managers. You can also register event handlers on nodes within the scene to handle user input or respond to changes in the application state.