Football is a team sport in which players compete to win by running the ball down the field and scoring points. The game also involves tackling opponents, catching passes and blocking members of the opposing team. Football requires a high level of physical fitness and teaches important life skills. It also improves cardiovascular health, builds muscles and improves balance and coordination.
A game of football begins with a kickoff, which occurs when one team kicks the ball off the sidelines and into play. The kicking team then attempts to advance the ball down the field, stopping the other team from stopping them (either by getting tackled or running out of bounds). The team that wins the kickoff receives first possession of the ball.
Each team has four attempts, called downs, to advance the ball ten yards toward their opponent’s end zone. If the offense fails to do so in four downs, the other team takes over possession of the ball. The defense’s goal is to stop the offense from advancing the ball by tackling ball carriers, breaking up passes and preventing them from getting into the end zone.
To score a touchdown, the offensive team must either run the ball across the opposition’s end zone or catch it there (which earns six points). The defensive team can also earn two points by tackling an opponent in his own end zone, which is known as a safety. In addition, the team that scores a field goal can earn three points by kicking it through a structure at the end of the field called the goal posts.
The game is played on a 100-yard field with a 10-yard end zone for each team. The field has a line, called the line of scrimmage, that marks the starting point for each down. There are also lines, called hash marks, that mark single-yard intervals down the field. The ball may only be thrown forward by a player on the offensive team once during each down, and only before crossing the line of scrimmage. If the ball touches the ground before being caught, it is an incomplete pass and the offense loses a down.
The quarterback is the leader of the offensive team and calls the plays that the players should follow on each down. Before a play, the team usually meets in a private area, called a huddle, to discuss the play. The huddle is usually conducted using codes so that the opposing team cannot hear them.
The offensive line consists of five players who protect the quarterback and clear the way for runners by blocking members of the opposing team. The center, left guard, right guard and right tackle all start on the line of scrimmage at the beginning of each play. The quarterback receives a snap from the center on each play, then hands or throws the ball to a running back or fullback for yardage or throws it to a receiver for a touchdown.