Is enum a map

public enum Direction {
    UP(KeyEvent.VK_UP), DOWN(KeyEvent.VK_DOWN), LEFT(KeyEvent.VK_LEFT), RIGHT(KeyEvent.VK_RIGHT);

    public final int vk;
    // constructor
    Direction(int vk) {
        this.vk = vk;
    }
    // Direction : type
    // fromVK : name
    public static Direction fromVK(int vk) {
        for (Direction d : values()) {
            if (d.vk == vk) {
                return d;
            }
        }
        return null;
    }
}

Why can we use values()? And the enum here is each of them has its own sequence of numbers, so Direction(int vk) can take int