A revolver is a type of firearm characterized by a cylindrical chamber that rotates to align with the barrel, allowing it to hold multiple rounds of ammunition. When the trigger is pulled, the chamber revolves to bring a fresh round into the firing position, and the hammer strikes the primer of the cartridge to fire the bullet. Revolvers are known for their simple and reliable design and are often favored for their ease of use and accuracy. They come in various calibers and are commonly used for self-defense, target shooting, and at one time were very popular sidearms for law enforcement personnel.