Semi-automatic, meaning it uses the energy of the fired cartridge to cycle the action of the firearm and advance the next available cartridge into position for firing. One cartridge fired each time the trigger of a semi-automatic pistol pulled; the pistol’s “disconnector” ensures this behavior.

Additional terms sometimes used as synonyms for a semi-automatic pistol are automatic pistolself-loading pistolautopistol, and autoloading pistol.

A semi-automatic pistol harnesses the energy of one shot to reload the chamber for the next. After a round discharges, the spent casing ejected and a new round from the magazine loaded into the chamber. This allows another shot fired as soon as the triggers pulled again. Most pistols use recoil operation to do this, but some pistols use blowback or gas operation.

Most types of semi-automatic pistols rely on a removable magazine to store ammunition before it fired, usually inserted inside the grip.