Early Heaven Ba Gua is an arrangement of trigrams representing the Perfect Universe where everything is in perfect harmony. Later Heaven Ba Gua is an arrangement depicting the Changing Universe. The later represents Qi, the seasons and the time in a dynamic order.
We can say that the theories come from the Early Heaven Ba Gua, and the application comes from the concept of the Later Heaven Ba Gua.
When you start learning BaZi, you discover how this new knowledge is great for finding your real goals in life. BaZi brings you a better knowledge of your character, your career, your relationships, even your possibilities for prosperity, allowing you to better navigate the road of life.