A Linebacker is commonly referred to as an LB.
Yes, it is a football term
Linebackers are part of the defensive team, and line up approximately 3 to 5 yards (4 m) behind the line of scrimmage, behind the defensive linemen, and therefore "back up the line."
Uau, that info is very complex.
In football, the formation describes how the players on a team are properly positioned on the field.
That position is priceless for a team in order to have a good game.
generally defines whether a player has a mostly defensive or attacking role, and whether they tend to play towards one side of the pitch or centrally.
Formations are typically described by three or four numbers, which denote how many players are in each row of the formation from the most defensive to the most forward. For example, the popular "4–5–1" formation has four defenders, five midfielders, and a single forward. Different formations can be used depending on whether a team wishes to play more attacking or defensive football,
Linebacker
A linebacker (LB or backer) is a playing position in American football and Canadian football. Linebackers are members of the defensive team, and line up approximately three to five yards (4 m) behind the line of scrimmage, behind the defensive linemen, and therefore "back up the line". Linebackers generally align themselves before the ball is snapped by standing upright in a "two-point stance" (as opposed to the defensive linemen, who put one or two hands on the ground for a "