Carbine

A carbine (pronounced /ˈkɑrbaɪn/ or /ˈkɑrbiːn/[1]) is a firearm similar to a rifle or musket. Many carbines, especially modern designs, were developed from rifles, being essentially shortened versions of full rifles firing the same ammunition, although often at a lower velocity. There have also been many cases where the carbine and rifle adopted by a particular nation were not technically related, such as using completely different ammunition or internal operating systems (though the carbine still being weaker, or of smaller size). Either may be more common, depending on the time period. There are also a limited number of pistol-caliber carbines, designed by integrating the action of a handgun such as a revolver or autoloader into a longer weapon with a rifle barrel and stock. They are generally employed as a more accurate alternative to a traditional handgun, and are used by some police teams and by civilian sport shooters.

In the 1800s, infantry would have a longer, more powerful firearm, and cavalry a shorter, lighter firearm.

The shorter length and lighter weight of carbines makes them easier to handle in close-quarter combat situations (such as urban or jungle warfare), or when deploying from vehicles. Carbines have higher penetration capabilities than submachine guns while retaining standardized ammunition, unlike most current personal defense weapons, which use proprietary cartridges. The disadvantages of carbines, when compared with their longer counterparts, are generally poorer long-range accuracy and shorter effective range, while also generally being larger than submachine guns and thus harder to maneuver in close quarters.

http://en.wikipedia.org/wiki/Carbine