Howitzer in the context of Fire support base

Artillery consists of ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during sieges, and led to heavy, fairly immobile siege engines. As technology improved, lighter, more mobile field artillery cannons were developed for battlefield use. This development continues today; modern self-propelled artillery vehicles are highly mobile weapons of great versatility generally providing the largest share of an army's total firepower.

Originally, the word "artillery" referred to any group of soldiers primarily armed with some form of manufactured weapon or armour. Since the introduction of gunpowder and cannon, "artillery" has largely meant cannon, and in contemporary usage, usually refers to shell-firing guns, howitzers, and mortars (collectively called barrel artillery, cannon artillery or gun artillery) and rocket artillery. In common speech, the word "artillery" is often used to refer to individual devices, along with their accessories and fittings, although these assemblages are more properly called "equipment". However, there is no generally recognized generic term for a gun, howitzer, mortar, and so forth: the United States uses "artillery piece", but most English-speaking armies use "gun" and "mortar". The projectiles fired are typically either "shot" (if solid) or "shell" (if not solid). Historically, variants of solid shot including canister, chain shot and grapeshot were also used. "Shell" is a widely used generic term for a projectile, which is a component of munitions.

Self-propelled artillery (also called locomotive artillery) is artillery equipped with its own propulsion system to move toward its firing position. Within the terminology are the self-propelled gun, self-propelled howitzer, self-propelled mortar, and self-propelled rocket artillery. They are high-mobility vehicles, usually based on continuous tracks carrying either a large field gun, howitzer, mortar, or some form of rocket/missile launcher. They are usually used for long-range indirect bombardment support on the battlefield.

In the past, self-propelled artillery has included direct-fire vehicles, such as assault guns and tank destroyers, which were typically well-armoured vehicles often based upon the chassis of a tank. In lieu of the standard tank's general-purpose main gun that fired both high-explosive and anti-tank ammunition, direct-fire vehicles had specialized roles, with assault guns providing close fire-support for infantry and tank destroyers mounting an anti-tank gun to take on enemy armour.

The M777 howitzer is a British towed 155 mm artillery piece in the howitzer class. It is used by the ground forces of Australia, Canada, Colombia, India, Saudi Arabia, Ukraine, and the United States. It was first used in combat during the War in Afghanistan.

The M777 is manufactured by BAE Systems' Global Combat Systems division. Prime contract management is based in Barrow-in-Furness in Cumbria, England, as well as manufacture and assembly of the titanium structures and associated recoil components. Final integration and testing of the weapon is undertaken at BAE's facility in Hattiesburg, Mississippi, US. Depending on the year, contract and systems package, the M777 has been exported with individual unit costs from US$2.025 million (in 2008) to $3.738 million (in 2017).

A shell, in a modern military context, is a projectile whose payload contains an explosive, incendiary, or other chemical filling. Originally it was called a bombshell, but "shell" has come to be unambiguous in a military context. A shell can hold a tracer.

All explosive- and incendiary-filled projectiles, particularly for mortars, were originally called grenades, derived from the French word for pomegranate, so called because of the similarity of shape and that the multi-seeded fruit resembles the powder-filled, fragmentizing bomb. Words cognate with grenade are still used for an artillery or mortar projectile in some European languages.

The formal definition of large-calibre artillery used by the United Nations Register of Conventional Arms (UNROCA) is "guns, howitzers, artillery pieces, combining the characteristics of a gun, howitzer, mortar, or rocket, capable of engaging surface targets by delivering primarily indirect fire, with a calibre of 76.2 mm (3.00 in) and above". This definition, shared by the Arms Trade Treaty and the Treaty on Conventional Armed Forces in Europe, is updated from an earlier definition in United Nations General Assembly Resolution 46/36L, which set a threshold of 100 mm (3.9 in). Several grammatical changes were made to that latter in 1992 and the threshold was lowered in 2003 to yield the current definition, as endorsed by UN General Assembly Resolution 58/54.

Historically, large-calibre weapons have included bombards and siege guns.

Fort Douaumont (French: Fort de Douaumont, pronounced [fɔʁ də dwomɔ̃]) was the largest and highest fort on the ring of 19 large defensive works which had protected the city of Verdun, France, since the 1890s. By 1915, the French General Staff had concluded that even the best-protected forts of Verdun could not withstand bombardments from the German 420 mm (16.5 in) Gamma guns. These new super-heavy howitzers had easily taken several large Belgian forts out of action in August 1914. Fort Douaumont and other Verdun forts were judged ineffective and had been partly disarmed and left virtually undefended since 1915. On 25 February 1916, Fort Douaumont was entered and occupied without a fight by a small German raiding party comprising only 19 officers and 79 men, entering via an open window by the moat. The easy fall of Fort Douaumont, only three days after the beginning of the Battle of Verdun, shocked the French Army. It set the stage for the rest of a battle which lasted nine months, at enormous human cost. Douaumont was finally recaptured by three infantry divisions of the Second Army, during the First Offensive Battle of Verdun on 24 October 1916. This event brought closure to the battle in 1916.

Fire support is a military tactics term used to describe the use of weapons and munitions aimed to support friendly forces by engaging, destroying or suppressing enemy forces, facilities, or materiel in combat. It is often provided through indirect fire (artillery) launched from the rear, though the term may also be used for some direct fire or aerial attacks performed by front line units to support other friendly units.

The United States Department of Defense defines fire support as "fires that directly support land, maritime, amphibious, and special operations forces to engage enemy forces, combat formations, and facilities in pursuit of tactical and operational objectives."

An autocannon, automatic cannon, machine cannon or anti-tank machine gun, is a fully automatic gun that is capable of rapid-firing large-caliber (20 mm/0.79 in or more) armour-piercing, explosive or incendiary shells, as opposed to the smaller-caliber kinetic projectiles (bullets) fired by a machine gun. Autocannons have a longer effective range and greater terminal performance than machine guns, due to the use of larger/heavier munitions (most often in the range of 20–60 mm (0.79–2.36 in), but bigger calibers also exist), but are usually smaller than tank guns, howitzers, field guns, or other artillery. When used on its own, the word "autocannon" typically indicates a non-rotary weapon with a single barrel. When multiple rotating barrels are involved, such a weapon is referred to as a "rotary autocannon" or "rotary cannon". If it uses a single barrel with a rotating cylinder with multiple chambers, it is known as a "revolver autocannon" or "revolver cannon"; both of these systems are commonly used as aircraft guns and anti-aircraft guns.

Autocannons are heavy weapons that are unsuitable for use by infantry. Due to the heavy weight and recoil, they are typically installed on fixed mounts, wheeled carriages, ground combat vehicles, aircraft, or watercraft, and are almost always crew-served, or even remote-operated with automatic target recognition/acquisition (e.g. sentry guns and naval CIWS). As such, ammunition is typically fed from a belt system to reduce reloading pauses or for a faster rate of fire, but magazines remain an option. Common types of ammunition, among a wide variety, include HEIAP, HEDP and more specialised armour-piercing (AP) munitions, mainly composite rigid (APCR) and discarding sabot (APDS) rounds.

A long gun is a category of firearms with long barrels. In small arms, a long gun or longarm is generally designed to be held by both hands and braced against the shoulder, in contrast to a handgun, which can be fired being held with a single hand. In the context of cannons and mounted firearms, an artillery long gun would be contrasted with a field gun or howitzer.

The 2S19 Msta-S is a 152.4 mm self-propelled howitzer designed and manufactured by Uraltransmash in the Soviet Union and later in Russia, which entered service in 1989 as the successor to the 2S3 Akatsiya. The vehicle has the running gear of the T-80, but is powered by the T-72's diesel engine.

A rocket-assisted projectile (RAP) is a cannon, howitzer, mortar, or recoilless rifle round incorporating a rocket motor for independent propulsion. This gives the projectile greater speed and range than a non-assisted ballistic shell, which is propelled only by the gun's exploding charge. Some forms of rocket-assisted projectiles can be outfitted with a laser guide for greater accuracy.

Horse artillery was a type of light, fast-moving, and fast-firing field artillery that consisted of light cannons or howitzers attached to light but sturdy two-wheeled carriages called caissons or limbers, with the individual crewmen riding on horses. This was in contrast to other forms of field artillery which may also be horse-drawn but were heavier and whose gunners either marched on foot or were transported seated on the gun carriage, wagons or limbers. Horse artillery units provided highly mobile fire support especially to cavalry units, and existed in armies in Europe, the Americas, and Asia, from the early 17th to the mid-20th century.