toString method - cant understand this example

class PointCoordinates {

	private int x, y;
	public PointCoordinates(int x, int y) {
		this.x = x;
		this.y = y;
	}
	public int getX() {
		return x;
	}
	public int getY() {
		return y;
	}
}

public class ToStringDemo {

	public static void main(String args[]) {
		PointCoordinates point = new PointCoordinates(10, 10);
		// using the Default Object.toString() Method
		System.out.println("Object toString() method : " + point);
		// implicitly call toString() on object as part of string concatenation
		String s = point + " testing";
		System.out.println(s);
	}
}