The offensive team or offense in American football or Canadian football, is the team that begins a play from scrimmage in possession of the ball. A play usually begins with the quarterback taking a snap from the center, and then either handing off to a back, passing to a reciever or a back, or running the ball himself.
The offensive unit in American football consists of a quarterback, linemen, backs, and recievers. The function of the linemen is to block. The line consists of a center, two guards, two tackles and one or two tight ends. Backs include halfbacks and a fullback, who usually block, run the ball, or receive a pass. The function of the wide receivers is to catch passes.
- center - the center performs the normal blocking functions of all linemen and, in addition, is the player who puts the ball in play by means of the snap.
- guard - the two guards are the offensive linemen directly on either side of the center and inside the tackles. Like all interior linemen, their function is to block on both running and passing plays. On some plays, rather than blocking straight ahead, a guard will "pull" in order to block a player on the opposite side of the center, in a running play called a "trap". Sometimes both guards will pull, in support of an outside running play called a "sweep".
- tackle - the offensive tackles play on either side of the guards. Their role is primarily to block on both running and passing plays. The area from one tackle to the other is an area of "close line play" in which some blocks from behind, which are prohibited elsewhere on the field, are allowed.
- tight end - the tight ends play on either side of, and immediatly next to, the tackles. They are a mix between a lineman and a pass receiver. If an end moves away from the tackle, he is called a split end. Modern formations may have only one tight end, and a wide receiver instead of a second tight end.
- wide receiver - the wide receivers are speedy pass-catching specialists. Their job is to run pass routes and get open for a pass. A wide receiver may line up on the line of scrimmage and be counted as one of the necessary 7 players on the line in a legal formation, or he may line up off the line of scrimmage and be counted as being in the backfield.
- halfback - the halfbacks may function as running backs, blocking backs or short-yardage receivers. In some formations, running back positions may have specialized names. In a traditional formation, there are two halfbacks. Modern formations may have only one.
- fullback - like the halfbacks, a fullback may do some running, some blocking, some short receiving. A classic fullback is more of a straight-ahead, "four yards and a cloud of dust" power runner than a halfback.
- quarterback - it all revolves around the quarterback