It's all about angular measurements over a given distance - they're as different as mph & km/h.
Minute of Angle (MOA) = 1 minute of angle
Milliradian (MIL) = 1 milliradian
1 MOA equals 1 minute of angle and 1 MIL equals one milliradian. MOA and MIL are not a measurement of inches, feet, yards, centimeters or meters (linear measurements).
1 Degree equals 60 MOA, or 17.78 MILS. At a given distance of 100 yards, 1 MOA will equate to 1.047”. 1 Mil ill be equal to 3.6” That same 1 MOA and 1 Mil adjustment at 1,000 yards equals 10.47” and 36” respectively.
Still need help? Call or ask the guys and gals behind the counter, they won't make you feel stupid for not knowing!