The mAh capacity rating refers to the storage capacity or Battery capacity available for a particular battery. A battery with a capacity rating of 1800 mAh could deliver a current of 1800mA for one hour. Higher mAh ratings for the same battery type will generally mean longer run times.
Nominal voltage: -
The average voltage a cell outputs when charged is called as its nominal voltage. Each Li-ion cell has nominal voltage of 3.7 Volts.
Max Current consumption load: -
This is the max current which will be consumed by the device or appliance. You can find this in your device data sheet.
Max current rating battery: -
The max current rating of battery can be found by multiplying the Battery capacity(in capacity) with the discharge rate( The C rating) of the battery and it refers to the max current the battery can supply.