The NFL and the AFL are two different types of leagues. The NFL is known as the National Football League. This is known to be the highest type of professional football league that can be found in the United States of America. This league is composed of 32 different teams. The other league is called the AFL that stands for Arena Football League.
It was 1987 when this league was first founded. What makes this different from the AFL is this specifies that this league will only allow Football to be played indoors. Another main difference between the two is that the NFL has 100 yards while the AFL only has half of that, which is 50 yards.