The picture above is of a training drill. It involves players at four spots i.e. Spot A,B,C, and D.
The drill starts when the player from Spot A passes the ball to the player at Spot B . The player at Spot B plays it back to Spot A . The player after receiving the ball back, plays it to the Spot C. From Spot C, the ball is played to the player at Spot B. The player at Spot B after receiving the ball, plays a through ball for the player arriving from Spot D. The player from Spot D runs forward to receive the through ball and after receiving it takes a shot at the goal which is saved by the goalkeeper.
These type of drills help the players to enhance their passing and shooting abilities which are the essential part of the beautiful game of football.