In American English, a pocket pistol is any small, pocket-sized semi-automatic pistol (or less commonly derringers, or small revolvers), suitable for concealed carry in either a coat, jacket or trouser pocket.
You can use a weapon that has the Ammunition property to make a Weapon Ranged Attack Roll only if you have Ammunition to fire from the weapon. Each time you Attack with the weapon, you expend one piece of Ammunition. Drawing the Ammunition from a Quiver, case, or other container is part of the Attack (you need a free hand to load a one-handed weapon).
Light
A light weapon is small and easy to handle, making it ideal for use when fighting with Duel Weapons.