The Principles of Attack and Defence
The principles of attack and defence give an indication of what a team is attempting to achieve at different stages in the game cycle.
When the team is in possession of the ball (which is different to the Law book definition which refers to a team in the opposition half):
The team in possession tries to advance the ball, by carrying or kicking the ball forward, in the direction of the opposing team's goal line.
The players of the team in possession can use both the lateral space across the field of play, and the linear space down the field to perform an attack, to eventually score.
A team in a possession maintains continuity of play by keeping the ball and
advancing the ball towards the opposition's goal-line.