What is Kung-Fu?    

The Tao is formless. The Tao exists since the beginning. The Tao have no beginning and ending. The meaning is very complex and difficult to understand. The meaning is too wide, so it is very difficult to be explained by the word clearly.
The simplest meaning of The Tao is "The Way" or can be said too as "The Law", "The Rule" and others.
The Tao is "Something" which exists behind all of process in the universe.
Everything can happen because there is a "Law", because there is a "Rule", because there is a "Way".  Everything can happen because of "The Tao".

The fish swims in the water but they don't realize 'the water'.
The bird flights riding the wind but they don't realize 'the wind'.
The man exists inside The Tao but they don't realize 'The Tao'.
Tao can shown the way but can't represent to walk on it.