cartridge

ot noun

1. The package consisting of the bullet, primer, and casing containing gunpowder; a round of ammunition.
2. (by extension) A prefabricated subassembly that can be easily installed in or removed from a larger mechanism or replaced with another interchangeable subassembly.
3. A vessel which contains the ink or toner for a computer printer and can be easily replaced with another.
4. Magnetic tape storage, used for storing (backup) copies of data.