Gun
In military usage, the word "firearm" is used for the type of weapons that soldiers carry. Most of them are either pistols or rifles. These small arms can be carried and used by one person. They have the same basic parts: a trigger, a barrel, and a handgrip or stock. The shooter's finger pulls the trigger to fire the weapon which releases a bullet. The barrel guides the bullet which then flies to the target. The shooter's hand holds the handgrip.