In Chinese medicine Qi (or Chi) is the energy that exists within our bodies and within the universe it is the energy that exists everywhere.
With regards to alternative wellness, masters of Qi, such as licensed acupuncturists, can use this energy to help alleviate pain, improve circulation, and increase our sense of well-being.
Qi flows through lines in our body called Meridians. If you've experienced acupuncture before you've probably felt Qi, as it's the pleasant tingling feeling flowing through you on a straight line.
Acupuncture not your thing? Well, then you're probably familiar with Qi as it's the main principle behind feng shui.