VBox is a JavaFX layout container used to arrange UI components in a vertical column. It arranges the child nodes in the order in which they are added to the container, and it allows developers to specify the spacing between the nodes.

Here is an example of using VBox to arrange two Button components:

VBox vbox = new VBox();
Button button1 = new Button("Button 1");
Button button2 = new Button("Button 2");
vbox.getChildren().addAll(button1, button2);

// Set the spacing between the buttons
vbox.setSpacing(10);

// Add the VBox to a parent container
Scene scene = new Scene(vbox, 300, 100);

In this example, a VBox container is created, and two Button components are added to it using the getChildren() method. The setSpacing() method is called to set the spacing between the buttons, and then the VBox is added to a Scene object.

By default, a VBox will lay out its child nodes so that they are centered vertically within the container. However, you can use the setAlignment() method to specify a different alignment for the children, such as Pos.CENTER, Pos.BOTTOM_LEFT, or Pos.TOP_RIGHT.

VBox is a simple and effective way to arrange UI components in a vertical column, and it can be used in a variety of different applications, from simple forms to complex user interfaces.