The ampere-hour or Amp hour is a unit of electrical charge (denoted Ah). The milli-ampere hour (abbreviated mAh) is one thousandth of an ampere-hour.
1 Ah is equal to 3,600 coulombs so 1 mAh is equal to 3.6 coulombs. The coulomb is the SI unit of electrical charge ("quantity of electricity"). Coulombs are another "view" on the same data.
A coulomb the charge transferred by a constant electric current of 1 ampere in 1 second.
