The point of control is simply the price at which the largest trading volume has been made over a period of time (buy/sales).
This point is a rare point in the market because it is an indicator that can be observed before and not exactly when the price change occurs. Most indicators say “here is the point where the price is about to change” but few can say so far in advance where the price will go. Therefore it is very useful data besides easy to calculate. It does not carry complicated mathematics like oscillators.
The Control Point (POC) can be viewed as a sort of center of gravity towards where the price is going to move. These also allow to optimize the stops from previous data of the market.
The POC also defines virgin control points or VPOCs. These are points of control that have not been touched by the price. The VPOC could also refer to the Volume Control Point.