A semi-automatic, or self-loading firearm

Firearm

A firearm is a weapon that launches one, or many, projectile at high velocity through confined burning of a propellant. This subsonic burning process is technically known as deflagration, as opposed to supersonic combustion known as a detonation. In older firearms, the propellant was typically...

 is a weapon which performs all steps necessary to prepare the weapon to fire again after firing—assuming cartridges

Cartridge (firearms)

A cartridge, also called a round, packages the bullet, gunpowder and primer into a single metallic case precisely made to fit the firing chamber of a firearm. The primer is a small charge of impact-sensitive chemical that may be located at the center of the case head or at its rim . Electrically...

 remain in the weapon's feed device or magazine. Typically, this includes extracting and ejecting the spent cartridge case from the weapon's firing chamber, re-cocking the firing mechanism, and loading a new cartridge into the firing chamber.