Those same europeans also made hand cannons, which are smaller, more portable cousins of fire cannons.

That eventually evolved into the arquebus, similar in shape to modern rifles but supported by a hook.

All of these required the gunman to light the powder by hand, and didn't have a trigger to pull. By attaching a bit of flammable twine to a movable piece on the gun, we got matchlock guns.

Instead of igniting the gunpowder by hand, the gunman pulled the trigger, which moved a bit of string so that it set fire to the powder.

Matchlocks still weren't the most practical, so people experimented with the design. After trying out wheellocks, snaplocks, and snaphances, they arrived at the flintlock.

These have a similar idea, but use a bit of flint on a "hammer" instead of twine. Pulling the trigger makes the flint strike metal, causing a spark and igniting the powder. These are the guns used by pirates!

Flintlocks evolved into percussion cap guns, which had a primer on the gun instead of a flint on the hammer. And those evolved into modern cartridge guns!