The front is high and the back is low. In Feng Shui, it is called sitting empty and facing full. There is no difference between sitting empty and full, because this is only the direction of a mountain and it doesn't mean anything. It's just that under normal circumstances, people usually sit full and stand straight facing the air.
Good or bad depends on sand and water. In layman's terms, use whatever the surrounding environment is suitable for. Grandpa Deng's ancestral grave is empty, high in the front and low in the back.