"Artillery adds dignity to what otherwise would be a vulgar brawl."
-Frederick the Great
The term "artillery" is used to describe any weapon that throws large missiles and requires more than one person to operate. In Civilization IV, the artillery technology refers specifically to the invention and production of large and powerful breech-loading weapons that fire shells rather than balls. Production of these weapons began in the latter half of the 19th century.
Artillery is defined in a number of ways. One is by the weapon's trajectory: a "direct fire" weapon has a relatively flat trajectory, while an "indirect-fire" weapon has a high arc, allowing the missile to be dropped on targets behind walls, hills or even mountains. Artillery is also defined by its mode of transport; some are "fixed" weapons that cannot be moved, others are "towed" by separate vehicles, and others are "self-propelled."
Today's artillery is extremely lethal. The weapons can fire missiles at targets miles away, their targets spotted from airplane or even satellite. Artillery shells may contain high explosives, shrapnel, fueled-air explosives, mines, or even poison gas. The primary limitation of artillery in modern warfare is its relative slowness; the big guns cannot keep pace with the fast-moving armor and mechanized infantry forces. Jet planes are often used in artillery's traditional role now.