Object of the game: To get the football into your team's end zone by passing, running or kicking it.
A football team is made up of 11 players in various positions that have different jobs. When both teams are on the field one team plays offense, which is the team that has the ball and is trying to score, and the other team plays defense, which is the team that is trying to keep their opponent from scoring and is also trying to steal the ball back.
The offense has 4 tries, called downs, to move the ball at least 10 yards toward their own goal. Each time the ball travels at least 10 yards the offense is awarded a first down. They can continue to move the ball toward their goal until they score (a touchdown or kicked field goal), or fail to get another first down and have to punt (kick) the ball away to the other team, or if the defense gets the ball back because of a fumble (offense drops the ball during a play and defense pick it up - it becomes theirs) or an interception (offense throw the ball and defense catches it - it becomes theirs).
A touchdown is worth 6 points. After a touchdown the offense tries to score the extra point which can be done either by running the ball into the end zone or kicking the ball between the goal posts. The defense will try to block the extra point. Once the extra point play is over, the ball goes to the other team which will now be playing offense, and the game starts again.
A field goal is worth 3 points. If, after 3 downs, the offense is too far away to score a touchdown but thinks they are close enough to kick a field goal, a kicker will come on the field and try to kick the ball between the goal posts. If they make the kick, they get 3 points. Whether they make they kick or not, the play is over, the other team gets the ball and the other team attempts to move the ball and score.
During game play, the referee can stop the game with a yellow flag because either the offense or defense has committed a foul called a penalty. Usually if a penalty is called, the team that committed the penalty looses yards meaning the ball is moved farther away from their end zone and they have farther to go in order to score.
A football game is divided into 4 time periods called quarters. The play clock starts and stops all through the game. Play stops at the end of each quarter and the teams switch directions on the field. Between the second and third quarter is a longer break called halftime. Both teams leave the field during halftime to meet with coaches to discuss how the first half went, they return to the field after a few minutes, stretch and warm up again, and play continues. The team that has scored the most points at the end of 4 quarters wins.