We can think of Qi as energy produced from food we take in and the air we breathe. This is energy assimilated by the body for us to use in daily life. Another way energy can be created is by gathering external Qi. This work, or practice of Qi is called Qigong. Qi=energy, Gong=practice. So, the practice of cultivating energy.
Qigong brings in nature's energy to fill our Dan Tien, our Sea of Qi, which is a reservoir for holding this energy. The gathering of nature energy is used to cleanse and then nourish internal organs. Qigong takes this energy and uses it to clean, to dust, to eliminate years of rust, ideas, coatings, conceptions of how your life should be. You do not even have to be aware what is there; it is a self-cleaning tool and therefore a self-healing process. The organs as a solid are yin; the activity of the organ is yang, moving energy. Yin and yang mutually benefit each other and are supported in their functions with this Qi energy.
There is no one "goal" of a Qigong practice, yet we can say that once we have dusted our house, then the structure and functions of the organs themselves can talk to each other. They are in harmony and work for our benefit and understanding. This is the mind/body/spirit connection. This brings back to our "Original Nature". Think of your child self, when you were happy, carefree, interested, excited that another day had come! How do you lose this? Dust Accumulation! Social conditioning, school conditioning, family expectations and the environments where you live and work all integrate into the energy being that you are today. The brain, body and spirit need cleansing. So, just as Mother Nature stirs up wind, water and fire to self-cleanse, so too, can we gather nature's Qi that activates these principals to purify and nourish our insides. Then, connections are made, your goal is clear, you have integrity, you have energy, you have strength to overcome obstacles in life. Your eyes are bright with Shen, your body is alive with Qi and you have connection with your wisdom center and the knowledge to conserve your Jing, your life force essence.