Offensive Positions:

QB – Quarterback
RB – Running Back
WR – Wide Receiver
TE – Tight End
LT – Left Tackle
LG – Left Guard
C – Center
RG – Right Guard
RT – Right Tackle
OT – Offensive Tackle
FB – Fullback
HB – Halfback
X, Y, Z – Typically WR Positions

Defensive Positions:

DE – Defensive End
DT – Defensive Tackle
NT – Nose Tackle
ILB – Inside Linebacker
OLB – Outside Linebacker
Sam – Strong-side Linebacker
Mike – Middle Linebacker
Will – Weak-side Linebacker
FS – Free Safety
SS – Strong Safety
LCB – Left Cornerback
RCB – Right Cornerback
SCB – Slot Cornerback
DB – Defensive Back
Nickelback – The 5th DB
Dimeback – The 6th DB