Players and teams:
In football, teams consist of 11 players. Each team tries to get the ball into the opposing teams end zone. There are 3 types of teams: Offensive, Defensive, and Special teams.
Offensive players are separated into the following groups: 7 linemen who play on the line of scrimmage, or the line where the bal is located; and backs who are placed in different positions behind the linemen. The Linemen are designated in the following ways:
The center starts the game by hiking the ball, passing it through his legs, to a player directly behind him. After that the other players form a barrier for the ball carrier, or the quarterback. Different player protect the quarterback and tackle the defense. The quarterback can hand off the ball, pass or run straight downfield with it. One formation is the T formation in which the quarterback hands off the ball to the fullback or other backs, and rushes. Wide receivers catch most of the plays and replace backs and ends on the line of scrimmage.
The defense team is made up of the defensive lines, linebackers, and defensive backs. The defense team uses any number of players that they can. On average have 3 or 4 linemen who primarily stop the quarterback. The 3 or 4 linebackers can stop runners cover the other teams receivers, etc. The defensive back or secondary, consist of 2 cornerbacks who cover receivers and 2 safeties who guard that are behind linebackers.
Special teams usually consist of players who only play in certain part of the game. For example, the kicker only plays at the beginning or half of the game and tries to kick the ball through the goal posts. The punter kicks the ball downfield only when the offensive team has to surrender it.
A team of seven officials usually looks over a football game. They include: a referee, an umpire, a linesman, a field judge, a line judge, a side judge, and a back judge. They enforce the rules. The referee is mainly the head of the outfit decided the calls etc. The umpire questions uniforms equipment etc. The linesmen mostly mark the balls at the end of each play. The field judge mainly times the game.