Milliampere-hours, often abbreviated as mAh, is a measure of the amount of electrical charge a battery can store and provide. Think of it like the fuel tank of a car but for electronic devices. The higher the milliampere-hours (mAh) rating, the more energy the battery can hold, and typically, the longer your device can run before needing to be recharged. So, in simple terms, a higher mAh value generally means a longer-lasting battery for your gadgets.