ammunition
Cartridge
used in rifles and handguns, with primer, gunpowder and a bullet
Shotshell
used in shotguns, with primer, gunpowder, wad, and slug or shot
the gauge must match exactly. also the length (which is after it's been fired)
centerfire
used for rifles, shotguns and handguns. primer is in the center of the casing. typically reloadable.
rimfire
primer is in the rim of the casing. low pressure loads. not reloadable.