A musket is a muzzle

Muzzle (firearm)

The muzzle of a firearm is the end of the barrel from which the projectile will exit.Precise machining of the muzzle is crucial to accuracy, because it is the last point of contact between the barrel and the projectile...

-loaded, smooth bore long gun

Long gun

The term long gun is used to describe classes of firearm and cannon with longer barrels than other classes. In small arms, a long gun is designed to be fired braced against the shoulder, in contrast to a handgun, while in artillery a long gun would be contrasted with a howitzer or carronade.-Small...

, fired from the shoulder. Muskets were designed for use by infantry

Infantry

Infantrymen are soldiers who are specifically trained for the role of fighting on foot to engage the enemy face to face and have historically borne the brunt of the casualties of combat in wars. As the oldest branch of combat arms, they are the backbone of armies...

. A soldier armed with a musket had the designation musketman or musketeer

Musketeer

A musketeer was an early modern type of infantry soldier equipped with a musket. Musketeers were an important part of early modern armies, particularly in Europe. They sometimes could fight on horseback, like a dragoon or a cavalryman...

.

The musket replaced the arquebus

Arquebus

The arquebus , or "hook tube", is an early muzzle-loaded firearm used in the 15th to 17th centuries. The word was originally modeled on the German hakenbüchse; this produced haquebute...

, and was in turn replaced by the rifle

Rifle

A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...

. The term "musket" is applied to a variety of weapons, including the long, heavy guns with matchlock

Matchlock

The matchlock was the first mechanism, or "lock" invented to facilitate the firing of a hand-held firearm. This design removed the need to lower by hand a lit match into the weapon's flash pan and made it possible to have both hands free to keep a firm grip on the weapon at the moment of firing,...

 or wheel lock and loose powder

Gunpowder

Gunpowder, also known since in the late 19th century as black powder, was the first chemical explosive and the only one known until the mid 1800s. It is a mixture of sulfur, charcoal, and potassium nitrate - with the sulfur and charcoal acting as fuels, while the saltpeter works as an oxidizer...

 fired with the gun barrel

Gun barrel

A gun barrel is the tube, usually metal, through which a controlled explosion or rapid expansion of gases are released in order to propel a projectile out of the end at a high velocity....

 resting on a stand, and also lighter weapons with Snaphance

Snaphance

A Snaphance or Snaphaunce is a particular type of mechanism for firing a gun . The name is Dutch in origin but the mechanism can not be attributed to the Netherlands with certainty. It is the mechanical progression of the wheel-lock firing mechanism and the predecessor of the flintlock firing...

, flintlock

Flintlock

Flintlock is the general term for any firearm based on the flintlock mechanism. The term may also apply to the mechanism itself. Introduced at the beginning of the 17th century, the flintlock rapidly replaced earlier firearm-ignition technologies, such as the doglock, matchlock and wheellock...

 or caplock and bullets using a stabilizing spin (Minié ball

Minié ball

The Minié ball is a type of muzzle-loading spin-stabilising rifle bullet named after its co-developer, Claude-Étienne Minié, inventor of the Minié rifle...

), affixed with a bayonet.

16th-century troops armed with a heavy version of the arquebus called a musket were specialists supporting the arquebusiers and pikemen formations.