American football, known in North America simply as football, and elsewhere as American football, gridiron or tackle football, is a team sport, derived from rugby football, between two teams of 11 players each, with one team playing on offense and the other on defense. It is known for its very physical style of play, as well as for strategies involved in game decisions. The objective of the game is to score points by advancing the ball into the opposing team's end zone. The ball can be advanced by carrying it (a running play) or by throwing it to a teammate (a passing play). Points can be scored in a variety of ways, including carrying the ball over the opponent's goal line, catching a pass thrown over that goal line, kicking the ball through the goal posts at the opponent's end zone, or t