the team on the field is playing defense
defense is when you are playing in the field. batting isn't really referred to as offense but when a team is at bat i guess you could say that.
The difference is that offense is when your team has the ball and defense is when you want to get the ball or tackle but in your case your going to rip the flag of the other person.
When you are on offense your team is up to bat. Defense your team is pitching and trying to get 3 outs on the opposing team.
Offense usually Attack and score goals, Defense are constantly defending and saving goals and preventing any lethal Attacks from the opposition.
offense defense baserunning pitching catching bunting slapping mental game coaching field maintenance
offence has the ball and defence trys to stop them
defense is as important as offence. defense is your first offense.