The AK-47 is a selective-fire, gas-operated 7.6239mm assault rifle, first developed in the Soviet Union by Mikhail Kalashnikov. It is officially known as Avtomat Kalashnikova but also has been come to known as the Kalashnikov, AK, or in Russian slang, Kalash.
A highly popular weapon, it's seen great success in the battlefield for centuries and still remains a popular firearm today. Developed originally with wood hand grips and a full stock, the AK platform has since evolved into other platforms including the AKM and the AK74.