When two opposing American football teams meet, the player positions on the gridiron (playing field) are determined by whether the football team is on offense or defense. The offensive, or team with the ball, competes against the reason, which keeps the offense from scoring. With the football in the center, each team faces the other.

Positions on the offensive line in football:

The attacking team is the one in control of the football. The offense’s main purpose as a unit is to advance the ball down the field into the opponent’s end zone to score — either by touchdown or field goal. Other scoring options exist, although they are mostly reserved for special teams. The tasks of the offensive are distributed among important positions:

Quarterback: The team’s captain. In the huddle, he calls plays, screams signals at the line of scrimmage, and takes the ball from the center. The ball is then handed off to a running back, thrown to a receiver, or run.

The person who snaps the ball to the quarterback is the center. On every play, he is in charge of the ball.

A running back is a football player who runs with the ball. Tailbacks, halfbacks, and rushers are used to describe running backs.

Fullback: A player who is in charge of blocking for the running back and pass-blocking for the quarterback’s protection. Short-yardage runners’ fullbacks are often larger than running backs.

Wide receiver: A player who eludes opponents and catches the ball using his speed and quickness. A team may deploy two to four wide receivers on anyone play.

Tight end: A guy that can play both receiving and block. This man lines up beside the offensive tackle to the right or left of the quarterback.

Left and right guard are the offensive line’s inner two members, whose responsibility is to block and protect the quarterback and ball carriers.

The offensive line’s outer two members are left tackle and right tackle.

Defensive positions in football:

The defense’s major goal in American football is to prevent the offense from scoring points by intercepting the ball, tackling offensive players, and generally stopping the crime from moving the ball closer to their end zone and creating scoring opportunities. The tasks of the defense are distributed among important positions.

Defensive tackles are the defensive line’s inner two members, whose purpose is to keep their places to stop a running play or run through a gap in the offensive line to pressure the quarterback or disrupt the backfield formation.

Defensive end: The defensive line’s outer two members. Their primary responsibility is to overcome offensive blocking and meet in the backfield to tackle the quarterback or ball carrier. They’re in charge of driving the ball carrier out of bounds or toward (into) the pursuit of their defensive colleagues on running plays to the outside.

Linebacker: These guys play behind the defensive line and are considered the team’s greatest tacklers. Most teams use three or four linebackers on every play, depending on the formation. Linebackers are frequently called upon to defend both the run and the pass.

The guys that line up deepest in the secondary – the last line of defense — are known as safety. They must defend the long pass and the run, and there are free safeties and strong safeties.

Players that line up in the wide field sections, usually opposite the offensive receivers, are known as cornerbacks.