Airsoft guns are often classified by their power source. Popular power sources for airsoft guns are Electricity, CO2, or Green Gas. When you see the letters AEG, you are being told that the airsoft product is powered by electric DC current. Those three letters actually stand for Automatic Electric Gun. Most often AEG airsoft is associated with carbine or PDW (Personal Defense Weapon) sized devices. These bigger airsoft guns have the needed room to hide the battery power source that runs the system. Yes, most AEGs are capable of selecting firing mode between single-shot, burst, or fully automatic.
The batteries that power AEGs might put out as little as 7.4 volts or as much as 11.1 volts. Additionally their shape and connection type might vary. It is important to know which style of battery is required for your AEG.
Beginner or entry level AEG airsoft guns will often come with a starter battery and charger.
Higher level AEGs are not sold with a battery or charger. Airsoft players who buy these types of airsoft guns often already own other higher end AEGs and have batteries in their gear stash or want to buy premium batteries to maximize their AEGs performance.