What's the dot?

Master Chen Zhonghua often mentions the Dot, so what's the dot?  In my current understanding, there are three kinds of dots:
1) One in my body
2) One in the opponent's body
3) One in outside of my and opponent's bodies (somewhere in space)

Any one of these dots is a fixed point.  It is a point that does not move. If it is in my body, this dot is not moved by my actions.  If it is in the opponent's body, it is a point that does not want to be moved, it is also the source of power. If that point is moved, the opponent has no power.  If it is in space, it is created by my interactions with the opponent to go around this fixed point.  This third kind is very difficult to have, and Master Chen can demonstrate it.