American football is a unique sport -- it is a game about gaining territory as much as it is about scoring points. When two teams step onto a football field, each is battling for every inch it can take from the other. Each team wants to defend the field that is behind it and invade the field in front of it. Ultimately, they want to gain enough ground to score a touchdown or field goal.
In this article, you will learn about the field, the positions, and how points are scored, with a focus on professional football rules. We will also look at some basic techniques for the offense and defense. To learn more about football, read How NFL Equipment Works and How the Physics of Football Works.
Football is a game of inches played on a field measured in yards -- English measurements are used to track movements on the field. Teams succeed based on how many yards they accumulate or allow. An official NFL football field is a rectangle that is 120 yards (110 m) long and 53 yards, 1 foot (49 m) wide. Most fields are covered in grass and set in an outdoor (open-air) stadium. Some fields are made of artificial turf, which you'll find in many of the indoor stadiums.