A pistol is a handgun, more specifically one with the chamber integral to its gun barrel, though in common usage the two terms are often used interchangeably. The English word was introduced in ca. 1570, when early handguns were produced in Europe, and is derived from the Middle French pistolet (ca. 1550), meaning a small gun or knife. In colloquial usage, the word "pistol" is often used to describe any type of handgun, inclusive of revolvers (which have a single barrel and a separate cylinder housing multiple chambers) and the pocket-sized derringers (which are often multi-barrelled).