In gridiron football, defensive backs (DBs) are the players on the defensive team who take positions somewhat back from the line of scrimmage; they are distinguished from the defensive line players and linebackers, who take positions directly behind or close to the line of scrimmage.
The defensive backs, in turn, generally are classified into several different specialized positions:
The group of defensive backs is known collectively as the secondary; being the second line of defense against the run after the linemen and linebackers, and the main line of defense against the pass. They most often defend the wide receiver corps; however, at times they may also line up against a tight end or a split out running back.
|Positions in American football and Canadian football|
|Offense (Skill position)||Defense||Special teams|
|Linemen||Guard, Tackle, Center||Linemen||Tackle, End, Edge rusher||Kicking players||Placekicker, Punter, Kickoff specialist|
|Quarterback (Dual-threat, Game manager, System)||Linebacker||Snapping||Long snapper, Holder|
|Backs||Halfback/Tailback (Triple-threat, Change of pace), Fullback, H-back, Wingback||Backs||Cornerback, Safety, Halfback, Nickelback, Dimeback||Returning||Punt returner, Kick returner, Jammer, Upman|
|Receivers||Wide receiver (Eligible), Tight end, Slotback, End||Tackling||Gunner, Upback, Utility|
|Formations (List) -- Nomenclature -- Strategy|