Ki (pronounced 'kee') is the energy all around us - our inner power, our breathing... our existence. Mostly in Japan it is refered to as "Ki" , China it is refered to as "Chi" or "Qi" and in Sanskrit it is known as "Prana".
Most people do not know of Ki. They see it in their everyday lives but do not recognise it as Ki and prefer to walk blindly.
With Ki, you can make energy balls, beams, or even enhance your performance and even make objects with it. The possibilities are endless.
When cultivated, it can be used for healing, breaking or self defense purposes.
To learn how to use your ki, it's the easiest way to put your hands close to eachother, but not touching, and start breathing properly. Concentrate on that, and then start visualising your energy filling your body. Don't push it, tke your time and let it come in every part of you. Then concentrate in putting that energy in your hands, and visualise it as a sphere between your hands..
If you are gifted a little more (ike me lol), you will probably feel that energy between your hands as soon as you put them near eachother.
More about Ki energy you can read at
http://www.genshinkidojo.com/kienergy/kienergypage.htmlor
http://www.kienergy.org/