Some handgun subtypes include derringers, single-shot pistols, revolvers, semi-automatic pistols, pepperboxes, and machine pistols. The overlapping variations in meaning of the words "pistol" and "handgun" are discussed below.

The word "pistol" is often synonymous with the word "handgun". Some handgun experts make a technical distinction that views pistols as a subset of handguns. Sometimes in American usage, the term "pistol" refers to a handgun whose chamber is integral with the barrel, making pistols distinct from the other main type of handgun, the revolver, which has a revolving cylinder containing multiple chambers. However, Commonwealth usage makes no distinction at a technical level—"pistol" may refer to revolvers, semi-automatics, or muzzle-loading/cap-&-ball handguns. For example, the official designation of the Webley Mk VI was "Pistol, Revolver, Webley No. 1 Mk VI", and the designation "Pistol No. 2 Mk I" was used to refer to both the Enfield Revolver and the later Browning Hi-Power semi-automatic.

The first pistols were made as early as the 15th century, but their creator is unknown. By the 18th century, the term came to be used often to refer to handheld firearms. Practical revolver designs appeared in the 19th century, and it was in that century that the (sometimes-observed) technical differentiation in usage from the words "pistol" and "revolver" developed, at that time differentiating the newer revolver from the single-shot pistols previously in use.[citation needed]

The word "pistol" is derived from the French pistole (or pistolet), which has these possible origins:

The general types of handguns are listed below in their order of historical appearance. Each type can be classified into many subtypes. Some of these types can also be differently classified using the general distinction between muzzle-loading firearms (loading from the front of the barrel) and breech-loading firearms (loading from behind the barrel).

Single-shot pistols are theoretically the simplest pistols. The earliest handguns were single-shot, muzzle-loading guns with ignition provided by inserting a smoldering match cord into a touch hole. As such, they were essentially nothing more than miniature cannons, small enough to be handheld.

Improvements followed in subsequent centuries, as various types of locks (ignition devices) were invented. In the matchlock, the separate match cord was affixed to a spring-loaded pivot which could be tripped by a trigger. In the wheellock, a mechanism analogous to that used in today's cigarette lighters replaced the smoldering match cord. In the 17th century, the flintlock, which strikes a flint against steel, appeared. (The flintlock, amazingly, remained state-of-the-art for some two hundred years.) In the 19th century, percussion caps were developed, followed shortly by modern integrated-primer cartridges, and hammers therefore traded their flint for firing pins.

Single-shot pistols continue to be manufactured today and are often used for target shooting and handgun hunting game, including big game. The most powerful handguns are capable of taking all game including elephant.

Not long after the very beginning of firearms, inventors began experimenting with multi-barreled weapons in the quest for the ability to fire more than one shot before needing to reload. Not surprisingly, all types of firearms were included in their efforts, from volley guns to analogously devised handguns. Before anyone had developed a practical capability for delivering multiple loads to one barrel in quick succession (which is how repeating fire is usually accomplished today), gun smiths were aggregating multiple loaded barrels into one place.

Some examples of multi-barreled pistols are: