The picture above is of a training drill. It shows two small goal posts at the left and right bottom corner. The Blue team is acting as the defending team, while the Yellow team is shown as the team attacking to score the goal.
The goalkeeper of the Yellow team starts the drill by passing the ball to the defender, who plays it to the central defender. The central defender then plays the ball forward to the attacker who receives the ball before playing it to the central midfielder. The central midfielder then plays a through ball to the right side. The player from the right flank runs past the Blue player to receive the through ball before finishing it in the small goal at the right side.
This drill really helps the players on attacking side as well as the players on defending side to enhance their skills for real match scenarios.