A cap gun is a toy firearm designed to make a loud popping sound when fired. It uses small paper or plastic caps that contain a small amount of explosive material. When the trigger is pulled, the cap is struck, creating a noise similar to a real gunshot, but without any projectile being fired. Cap guns are often made of plastic or metal and are popular among children for imaginative play. They come in various designs, resembling real firearms or cartoonish versions. While they are generally considered safe, supervision is recommended during play to ensure responsible use.