Each position on a football team has its own important diverse set of responsibilities within the framework of actually playing the game against an opponent. Below are what each position does on the field of play:
QUARTERBACK
The Quarterback is not only the leader of the offense, he is also the leader of the team. He handles the ball on every offensive play and is reasonable for throwing the ball or handing it off to the teams running back. This job is to make sure the ball doesn't get thrown to the other teams' players. He makes quick decisions under pressure, make sure the offense has the right play called against what he sees the defense ready to do, avoid turnovers and be in contact with coaches and understand the offense he's playing.
WIDE RECIEVER
Wide receivers catch passes from the quarterback. They line up close to the edge of each side of the field and after the ball is snapped, they run downfield on a coordinated path trying to shake defenders and get open enough where the quarterback feels comfortable enough to throw them the ball. They also are asked to block defenders on running plays. Their primary function is gaining yards and scoring touchdowns by catching passes.
THE OFFENSIVE LINE
This position consists of five players, one center, 2 guards, and two tackles. The center, like the quarterback touches the ball every offensive play and gets the ball safely to the quarterback so he can dish the ball off to the correct offensive player. Both guards play one each on each side of the center and help the center handle pressure from the opposing team coming from the middle of the offense. The two tackles play further out from each guard and have the hardest job of all the players on the offensive line. They have to protect the quarterback from the largest and fastest players, and the defense has and have to be smart and quick on their feet to handle the best players from the other team.
LINEBACKER
The linebacker position has multiple responsibilities and requires versatile athletes to play it. They must be able to tackle running backs on running plays as well as cover tight ends when they leave the line of scrimmage on passing plays. The position requires speed, strength, intelligence and instincts in the hopes of disrupting the offense and getting the ball back to their own offense.
RUNNING BACK
This position carries the ball on running plays. Running backs aim to gain yards running the ball and score touchdowns. They can catch passes and block for the quarterback when the defense blitzes. They contribute both running and catching the ball.
TIGHTEND
The tight end is a blended position in that it combines catching potential of a wide receiver with the duties of sometimes having to stay in with the offensive line and block on running plays. They lineup end of the offensive line depending on what play is called. They tend to be larger and slower than wide receivers as a result but are called upon to catch passes for yards and score touchdowns. A good tight end can transform an offense from good into a powerhouse.
DEFENSIVE LINE
This position consists of ends and tackles. The tackles play inside the ends and are mostly there to control the inside of the line and prevent running plays from coming at them. The ends are the players who are usually the fastest on the line and their job is to rush and put pressure on the quarterback to disrupt his timing with wide receivers and create chaos and incomplete passes.
CORNERBACK
The cornerback's job is to cover wide receivers when they leave the line of scrimmage to try to catch passes from the quarterback. They use speed, agility, and instincts to try to force incomplete passes and tackle the wide receiver if he does happen to catch the pass. This position can also try to intercept passes attempted between the quarterback and the wide receiver and advance the ball the opposite way for his team. This is called an interception.
SAFETY
This position is the last line of defense, ideally preventing big plays from the offense. They cover deep passes, tackle receivers and intercept passes if possible. They are the players that play the farthest back from the line of scrimmage and their job is to watch the quarterback, make tackles on runs and passes if needed, and get the cornerbacks into the right position before the ball is snapped. They are the last position to try to stop touchdowns when the other players on defense aren't able to.
KICKER
This position kicks field goals, extra points and kickoffs, like punters and even more so, they must be accurate as well as be able to kick the ball far. They need to be cool under immense pressure as one missed or blocked kick can cost their team the game as they are often called on to attempt a game ending kick that can win it or lose it for their team. One of the most important positions on the team, their role is extremely important, especially in close games.
PUNTER
When the offense fails to make the required 10 yards on the previous 3 plays as stated in the rules, the head coach can decide to abandon the series and punt the ball back to the other team in order to get his offense back on the sidelines to regroup and strategize. The punters job is to kick the ball away to the other team, hopefully pinning the opposing offense deep within their own territory, flipping field position to benefit their team and put the other offense in a bad field position. The punter must be accurate and precise in order to be able to place the ball where coaches think would be least beneficial to the opponent.