American football (American football is usually referred to as football), also known as American football, is a kind of rugby sport, the most popular sport in the United States, and the first of the four major professional sports in North America. American football originated from English football,After it was introduced into the United States, the rules were changed, and the offensive and defensive lines were used for round-based scrimmage. There was no movement restriction, and the ball could be thrown forward. The purpose of this movement is to push the ball into the opponent's end zone to score. The scoring methods are as follows: Various, including holding the ball over the baseline, throwing it to a teammate behind the baseline, or kicking the ball straight on the ground through the middle of the two goalposts. The team with the most points at the end of the game wins.American football is a highly confrontational contact sport. Because there are often strong physical collisions with opposing players in the game, players need to wear helmets and protective gear.