Zones are slow in the sense that they wait for the offence to make the move. With man to man and full court press players are running all over the court, but in a zone the defenders stay in set position moving only a little bit either side as required. 3-2 zone is a good defence against run and gun. Run and Gun creates a lot of outside shots, and a 3-2 zone will help defend this by having 3 players guard the outside rather than 2.