American football (referred to simply as “football” in the United States and Canada) is a team sport played by two teams of eleven players on a rectangular field with goalposts at each end. The offense – the team with possession of the oval-shaped ball – attempts to advance down the field by running with the ball or passing it. While the defense – the team without possession of the ball – aims to stop the offense’s advance and to take control of the ball for themselves. Points are scored primarily by advancing the ball into the opposing team’s end zone for a touchdown or kicking the ball through the opponent’s goalposts for a field goal. The team with the most points at the end of a game wins. This game is not only the most popular sport in the United States in terms of broadcast viewership audience, but also the favored in Canada and other countries in North America. In United State, In the US, most major football teams compete in the NFL and NCAA tournaments. However, there are still many other football teams that play freely. In addition, other football teams from Canada and Australia are also supported by the Americans.