OFFENSE: The 11 players who attempt to score.
QUARTERBACK (QB): Receives the snap and passes the ball or hands it off.
RUNNING BACK (RB): Gets handed the ball from the quarterback, then tries to run through all the defensive players.
WIDE RECEIVER (WR): Catches the ball thrown by the quarterback.
OFFENSIVE LINE: They keep the defense away. Line positions include the center (who snaps the ball into play), guards, and tackles.
TIGHT END (TE): Either acts like an offensive lineman or catches the ball like a wide receiver.
DEFENSE: The 11 players who attempt to stop the opposing team's offense.
DEFENSIVE LINE (D): The defensive ends and tackles who battle head-to-head against the offensive line.
LINEBACKER (LB): A player who lines up behind the defensive line to tackle the quarterback or defend against the pass or run.
DEFENSIVE BACK: The so-called secondary defends against the pass from the QB and helps stop the run.
SPECIAL TEAMS: The players used in kicking situations (punts, field goals, kickoffs).
KICKER: A player who tries to kick field goals. He's also responsible for the kickoff.
PUNTER: A player generally brought in to turn the ball over to the opposing team on the fourth down.
RULES: During four 15-minute quarters, the offense tries to run, pass, or kick the ball into the end zone.
KICKOFF: The kick that puts the ball into play to start the first and second halves, or after a touchdown or a field goal.
TOUCHDOWN: OK, everyone knows this. It's worth six points.
EXTRA POINT: A kick, worth one point, that's attempted after a touchdown. The ball must pass through the end zone's goalposts.
SAFETY: A score, worth two points, when an offensive ball carrier is tackled in his own end zone.
TWO-POINT CONVERSION: After a touchdown, the offense can try to score two points by running or throwing the ball into the end zone.
FIELD GOAL: A kick, worth three points. It's usually tried on a fourth down from inside 45 yards of the goalposts.