BorderPane is a JavaFX layout container used to arrange UI components in a border layout, where the components are arranged around the edges of the container. It allows you to place components in the top, bottom, left, right, and center positions of the container.

Here is an example of using BorderPane to arrange three Button components:

BorderPane borderPane = new BorderPane();
Button button1 = new Button("Button 1");
Button button2 = new Button("Button 2");
Button button3 = new Button("Button 3");

borderPane.setTop(button1);
borderPane.setLeft(button2);
borderPane.setRight(button3);

Scene scene = new Scene(borderPane, 300, 200);

In this example, a BorderPane container is created, and three Button components are added to it using the setTop(), setLeft(), and setRight() methods. The buttons will be aligned in the top, left, and right positions of the BorderPane, respectively.

You can also set a component to be in the center position of the BorderPane using the setCenter() method. If multiple components are added to a single position, they will be stacked on top of each other in the order they were added.

BorderPane is a powerful layout container that allows you to easily create complex layouts for your user interfaces. It is commonly used in applications that require a navigation pane, a content pane, and a footer, for example.