Mechanics
Cycling
The full sequence a self-loading firearm performs to fire, extract, eject, and chamber the next round.
Cycling is the cycle of operation a semi-auto completes for each shot: fire, unlock, extract the spent case, eject it, cock the hammer or striker, strip a fresh round from the magazine, chamber it, and lock up ready to fire again. When all steps happen reliably, the gun 'runs'; when a step fails, you get a malfunction.
Reliable cycling depends on adequate power (ammo and gas), good magazines, proper lubrication, and a firm shooting platform. Underpowered ammo, a dirty or dry gun, weak magazine springs, or 'limp-wristing' a pistol can all interrupt the cycle and cause stoppages.