This article explains energy, power, milliamp hours, kilowatt hours, and other units. It will also teach you how to make loads of calculations involving how much energy different appliances store, how much it would cost to charge electrical appliances etc so you can figure out how to save electricity and if your new efficient appliance is going to save you money.
This is a companion discussion topic for the original entry at https://gurgleapps.com/learn/electronics/mah-milli-amp-hours-kwh-kilowatt-hours-power-and-energy