The offensive team in football is the team in possession of the ball, trying to score points against the other team's defense. There are 11 players at various positions on the field for the offense on every play, just as there are for the defense. The foundation of the offense is the offensive line. This is a group of five players – usually very large players – who are responsible for keeping defenders away from the quarterback and for creating holes for the running backs to run through.

There are three main offensive line positions: center, guard and tackle. The center lines up directly in the middle of the line and is the player who snaps the ball to the quarterback to begin a play. There are two guards, one on either side of the center; and there are two tackles, one on each end of the line. The tight end can also be considered one of the offensive line positions, as he typically lines up directly outside one of the tackles. However, tight ends are not used on every play, and they often go out to receive passes, whereas linemen are almost always used for blocking.

The offensive linemen are aligned along what is called the line of scrimmage, an imaginary line extending horizontally from the ball to both sidelines. The only other offensive positions that line up on the line of scrimmage are wide receivers. Receivers are generally very athletic, as they must be able to outrun speedy defensive backs, catch passes and run after the catch. There are variations among receiving positions, such as flanker and split end – these terms refer to specifically where the receiver lines up on the field.

Among the positions that are lined up behind the line of scrimmage, the running backs are the farthest from the line. The most common types of running backs are halfbacks or tailbacks, who are generally smaller and faster and do most of the ball-carrying, and fullbacks, who are usually bigger and slower and more often than not are asked to block for the halfbacks. The fullback usually lines up closer to the line than the halfback.

Out of all the offensive positions on a football team – and all the positions on either side of the ball, really – the most important is widely considered to be the quarterback. The quarterback is the player who calls the offensive plays in the huddle, examines the defense at the line of scrimmage to determine where the play should go, and takes the ball from the center to begin the play. The quarterback then either hands the ball off to a running back or attempts to throw to a wide receiver, tight end or running back to move the ball down the field.