In modern usage, the terms "single-action" and "double-action" almost always refer to handguns, as few (if any) long guns feature double-action triggers. In handguns, genuinely single-action triggers with external hammers now are only seen on revolvers, while pretty much all semi-automatic pistols that support single-action firing are actually DA/SA hybrids, which is technically a two-stage double-action trigger with the cocking (first) stage being separately operable (hence can be "skipped" by the trigger). The longevity of purely single-action triggers on revolvers is mainly due to the gun's design layout – the revolver action relies on a rotating cylinder without using any reciprocating slide/bolt that can prohibit the shooter placing the fingers near the hammer for easy access, and it's not uncommon to see revolver shooters "fanning" the hammer to perform rapid single-action firing. While a "single-action" revolver or semi-automatic pistol must always be cocked prior to firing (either manually or by the operation of the weapon), most "double-action" handguns are capable of firing in both single- and double-action modes. Only "double-action only" weapons are incapable of firing from a cocked hammer.