mA is the unit (milli Ampere) used for the charging current, which you can compare to "the speed of charging". The higher the mA the faster eneloop batteries will charge. mA is also used for the discharge current. Eneloop chargers generally charge between 150 and 1500mA depending on the charger. mAh stands for milli Ampere hour. This refers to the amount of energy (capacity/charge) that a battery contains.  On every Eneloop there is a mAh number written. This is the total capacity the battery can contain.  A regular white Eneloop AA has a capacity of 1900mAh.