How does a handgun fire a bullet?

you pull the trigger, which causes a hammer to strike the back of the bullet, which has a very small amount of explosive on the end so it lights when struck. then the gun powder in side the bullet ignites, causing a small explosion that raises the pressure inside the barrel temporarily and forces the projectile part of the bullet out. the bullet casing my come out of the gun automatically, or you may have to take it out manually depending on the type of gun. there's a lot more detail behind the mechanics of a gun, but this is a simplified version