The modern history of American football can be considered to have begun after the 1932 NFL Playoff Game, which was the first American football game to feature hash marks, the legalization of the forward pass anywhere behind the line of scrimmage, and the movement of the goal posts back to the goal line
Each NFL season begins with a three-week preseason in August, followed by the 18-week regular season which runs from early September to early January, with each team playing 17 games and having one bye week. Following the conclusion of the regular season, seven teams from each conference (four division winners and three wild card teams) advance to the playoffs, a single-elimination tournament that culminates in the Super Bowl, which is contested in February and is played between the AFC and NFC conference champions. The league is headquartered in New York City.
To learn more about it click on this video:
NFL