Soldier rifle firing bullet shell smoking

A soldier is a member of the land component of national armed forces; whereas a soldier hired for service in a foreign army would be termed a mercenary. The majority of cognates of the word "soldier" that exist in other languages have a meaning that embraces both commissioned and non-commissioned officers in national land forces.

A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves ("rifling") cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile (for small arms usage, called a bullet), imparting spin around an axis corresponding to the orientation of the weapon. When the projectile leaves the barrel, this spin lends gyroscopic stability to the projectile and prevents tumbling, in the same way that a properly thrown American football or rugby ball behaves. This allows the use of aerodynamically-efficient pointed bullets (as opposed to the spherical balls used in muskets) and thus improves range. The word "rifle" originally referred to the grooving, and a rifle was called a "rifled gun." Rifles are used in warfare, hunting and shooting sports.

Typically, a bullet is propelled by the contained deflagration of an explosive compound (originally black powder, later cordite, and now nitrocellulose), although other means such as compressed air are used in air rifles, which are popular for vermin control, hunting small game, formal target shooting and casual shooting ("plinking").