American football originated in the United States in the late 19th century and has since spread around the world. It is a sport played by two teams of 11 players on a rectangular field with goals at each end. The aim is to advance the ball into the opponent's end zone by running with it or passing it to score points. Players have different roles on offense and defense, with the quarterback leading the offensive plays and defensive linemen and linebackers trying to stop the other team's progress. Women's American football leagues also exist at both the collegiate and professional levels.

2. American football is a sport team which was born in the USA .
The National Football League was the professional league with more audience .
The football championship are held in various parts of the world .
In the USA it has been in the National Football League since 1922 .
In the United States spread rugby that originated from the American Football .
In 1880 Whalter Camp introduced the grid for the start of each game.

3. Matches are played by two teams with eleven players head .
The most important role is played by the quarterback with its launches should
help the team win .The games lasts 60 minutes divided into four times 15
minutes each .
The range consist of 2 doors that are located at the ends of the playing field .
The lines which indicate Yards are arranged transversely to the field and the
ball used is oval .

4. scopo
The aim of the game is to conquer the territory : advancig on several
occasions on the lines players must reach the goal of opponents, put the
ball and score the touchdown .
The ultimate goal is to achieve more points than the opposing team .
Points can be scored by players in attack by kicking the ball over the end
zone between the two poles that mark the goal (field goal ) .
Even the defenders can achive points , blocking the movements of
opponents in their area of half or bringing the ball into touchdowns .
The Kick-off is done at the beginning of the two times and after each
signature .
Attempts to reach the goal are called «downs» .
The beginning of the action is when the ball is passed from the center to the
quarterback . The ball can move in two ways , led by a player in the running
or launched forward with a pass .

5. Roles
1.Center : he is the player who is at the center of the line of attack and that puts
the ball in play .
2. Quarterback : he gives the order to start action and coordinates the team
play on offense .
3.Tight end : he receives the lauches and blocks opponents .
4.Running back : he starts from behind the line of attack whit the ball .
5. Wide receiver : he must receive steps away and anticipate the offensive
action of the opponents .
Attack :

6. 1. Defensive Tackle : he stops the race opponents .
2. Linebacker : he follows and blocks the action of running , defends
the steps of opponents and disrupts the action of launch.
3. Cornerback : he defends the outer sides of the field from the steps of
the opponent .
4. Free Safety : he follows the receiver opponents and plate them .
Defence :

7. Football Girls
The football girls is practiced at a competive level in the United States and
other countries . In some cases , players have been included in the men’s
team particulary in the US Collegiate Championships .
HISTORY :
The first championship since 1965 when the Women's Professional
Football League was founded.
The highest-rated North America league is now the Independent Women’s
Football League , founded in 2000, with teams in the United States of
America and Canada .