A Flak Gun is an anti-aircraft artillery piece designed to target and destroy enemy aircraft. The term "flak" comes from the German word "Fliegerabwehrkanone," which translates to "aircraft defense cannon." These guns fire explosive shells that detonate in the air, creating shrapnel to damage or destroy planes. Flak guns were widely used during World War II by various military forces, including the German Army and the Allied Forces. They come in different calibers and configurations, ranging from smaller, mobile units to larger, fixed installations. Their effectiveness diminished with the advent of guided missiles and advanced air defense systems.