American football, known in the United States and Canada simply as football (Canada also has its own slightly different version, Canadian football), is a competitive team sport known for combining strategy with physical play. 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 tackling an opposing ball carrier within his end zone. The winner is the team with the most points when the time expires.
The sport is also played outside the United States. National professional and collegiate leagues exist in United Kingdom, Germany, Italy, Switzerland, Finland, Sweden, Japan, Mexico, Israel, Spain, Austria, and several Pacific Island nations. The National Football League (NFL), the largest American professional football league in the world, ran a developmental league in Europe from 1991–1992 and then from 1995–2006.
American football is closely related to Canadian football, but with significant differences. Both sports originated from rugby football. The major forms of football in the United States are collegiate football and professional football. There have been numerous major professional football leagues in the U.S., but currently the only one in existence is the NFL.