A pistol was a type of weapon. Franco DeSalvo possessed one. Pistols were a favorite of smugglers, soldiers, police, and any civilian wishing to be discreetly armed. They are small and lightweight(for the most part), and are able to be fired in one hand. Types of pistols are described below.
Projectile pistols: One-handed guns that fired bullets or darts are called projectile pistols. They are the most common type of pistol seen. Most of the Serenity crew were seen using one at least once. Malcolm Reynolds uses a multi-action pistol that he admits is one of the things that got him through the war. He, Jayne Cobb, and Zoe Washburne almost always carry at least one. Projectile pistols include semi-automatic pistols and revolvers.
Machine pistols: Machine pistols are either fully-automatic versions of existing pistols or scaled-down submachine guns. They are more handy than a submachine gun with the same power, but are generally much harder to control. Some exceptions are the machine pistols used throughout Serenity, mainly by Jayne but also by Kaylee, Zoe, and Simon.
Stun guns: A stun gun is an Alliance weapon used by security personnel as a more compact alternative to the sonic rifle, although harder to use with accuracy. It fires an energy bolt that stuns people and knocks them off their feet. Headshots or consecutive hits are able to kill, so good training is necessary to prevent this. Though not mentioned in the series or movie, stun guns use power at a voracious rate and can only fire once a few seconds. The only known use of this weapon is by the operative against Malcolm Reynolds in Serenity.
Laser pistols: A laser pistol is an energy weapon that fires an extremely powerful beam of destructive laser radiation. Laser pistols are rare and highly illegal for civilian use, as well as being terribly expensive. There are several problems to laser pistols that have yet to be solved. They use up their battery life very quickly. They cannot use batteries that aren't designed specifically for that weapon. The batteries are rare, expensive, non-rechargeable, and are difficult to replace in combat. The weapons are also susceptible to overheating, which will not only melt the weapon's battery casing, it will also release deadly radiation. For this reason, it is highly advisable to fire them in short bursts that will not overheat the weapon. However, laser pistols are popular among rich criminal bosses, namely Rance Burgess. Advantages to laser pistols are the huge damage, pinpoint accuracy, incredible range, light weight, and total lack of recoil. Crime lords also like them for their intimidation factor. Using a laser pistol is a sign of brutality, wealth, and total disregard for the law. Ironically, the Alliance, whose law banns laser weapons, frequently uses them itself.
Dart pistols: Dart pistols are small weapons that fire fletchettes laced with poison, usually fired by compressed air or CO2. Many also have anesthetics so the victim does not realize they are hit. They are silent and are so used for assassinations, though they do have combat applications, such as taking out officers quietly. Notable users of poison dart pistols are reavers.