Short answers, pulled from the story.
The 1933 NFL season introduced the two-division format and the first NFL Championship Game, which the Chicago Bears won over the New York Giants. Three new teams joined the league, and the rulebook was substantially revised to separate professional football from college rules.
The Pittsburgh Pirates, the Philadelphia Eagles, and the Cincinnati Reds all entered the NFL for the first time in 1933. The league also welcomed back the Boston Braves under a new name, the Boston Redskins, after they relocated within the city.
The Bronko Nagurski Rule made the forward pass legal from anywhere behind the line of scrimmage, removing the previous requirement that the passer stand at least five yards back. It was named after Nagurski's controversial touchdown pass in the 1932 NFL Playoff Game.
Harry Newman of the New York Giants led the NFL with 973 passing yards, setting a new record. Jim Musick of the Boston Redskins set a rushing record with 809 yards, and Paul Moss of the Pittsburgh Pirates led receivers with 283 yards.
The goal posts were moved from the back of the end zones to the goal lines in 1933 to increase the number of field goals and reduce the number of tie games. The change reversed a rule adjustment that had been made before the previous season.
George Halas fired his head coach Ralph Jones and resumed coaching duties himself in order to save money. Halas then led the Bears to victory over the New York Giants in the first NFL Championship Game at the end of the season.