The conferences were introduced when the AFL-NFL merger took place in 1970
Like all American professional sports leagues, the NFL splits its teams into two conferences: the AFC and NFC.
But is there much difference between the two conferences? Functionally, no.
The two names — American Football Conference and National Football Conference — are a byproduct of the AFL-NFL merger in 1970.
The former rival leagues joined to make one league with each of the AFL teams making up the AFC, along with the Baltimore Colts, Cleveland Browns, and Pittsburgh Steelers, who joined from the NFL. The 13 remaining NFL teams formed the NFC.
So while there are no rules differences between conferences as there are in baseball with the designated hitter, there are historical differences between the teams. Since the NFL was founded decades before the AFL, many NFC teams have a far richer history than their AFC counterparts.
Each of the six oldest franchises (Arizona Cardinals, Chicago Bears, Green Bay Packers, New York Giants, Detroit Lions, Washington Football Team) are in the NFC, and the average founding year for NFC teams is 1948. Compare that to the AFC, home to 13 of the 20 newest teams, where the average franchise was founded in 1965.
Still, AFC and NFC teams rarely see each other outside of the preseason, Pro Bowl and Super Bowl. Teams only play four interconference games per season — all against teams in the same division — meaning that an NFC team will only play a given AFC opponent in the regular season once every four years and only host them once every eight years.
If there is one difference between the leagues, it's one trophy they're able to win. Since 1984, NFC champions have been awarded the George Halas Trophy, named for the late Bears owners, while AFC champions win the Lamar Hunt Trophy, named for the AFL and Kansas City Chiefs founder. But, of course, nobody plays just to make the Super Bowl; it's the Lombardi Trophy that counts.