Who Is Your Noble Person? Understanding Its Meaning in the Five Elements and Bazi

Two ladies, Carrie and Freda, are discussing the Five Elements and Bazi. 

Carrie is a lady interested in learning about the Five Elements and Bazi, while Freda is a Lady with her own understanding and practice of the Five Elements and Bazi.

We all know FATE, and understand LUCK, but what exactly is QI?

Fate: The framework of time and space at a person's birth.
Qi: The natural essence of the Four Pillars at a person's birth.
Luck: the constantly changing external environment after a person's birth.