The Offense - What are they trying to do?

The aim of the offense is to score points. To do that they must maintain possession of the ball. The offense gets 4 chances (called "DOWNS") to progress the ball 10 yards forward. If they do, they will start at the first down again, and have another four more downs to move the ball forward 10 yards. This continues until they score or fail to move the ball the required 10 yards and turn the football over to their opponents.

Before each down, the offense goes into a huddle - a team meeting on the field. The Quarterback tells the team the play for that down. The team is told all the details for that play, including who gets the ball, whether it's a run or a pass, when the ball will be snapped, and to what side of the line the play will occur.

There are a variety of player combinations (called "FORMATIONS") that the offense can use to move the football down the field, and Coaches will vary the formation depending on the defense, the Down and field position. A basic Formation includes -

"OFFENSIVE LINEMEN" Five players (two "TACKLES", two "GUARDS", and one "CENTRE") who run in front of the ball carrier prevent the defense from tacking him, or drop back a step and form a wall to protect the Quarterback on passing plays.
"RECEIVERS" Three players who are eligible to catch a pass. The Receiver closest to the Offensive Linemen is called the "TIGHT END" while the two closest to the sideline are called "WIDE RECEIVERS".
"RUNNING BACKS" Two players who are the work horses of the team. The "FULLBACK" is like a freight train, able to move straight ahead and carry most of the opposing team at the same time. The "TAILBACK" is the speedster on the team who takes the ball wide on running plays.
"QUARTERBACK" He is the Field General and the starting point for the majority of plays. He will take the ball from the Centre, and either hand it to a Running Back or pass it downfield to a Receiver.