Front line in the context of "Forward air control"

A tank is an armoured fighting vehicle intended as a primary offensive weapon in front-line ground combat. Tank designs are a balance of heavy firepower, strong armour, and battlefield mobility provided by tracks and a powerful engine; their main armament is often mounted within a turret. They are a mainstay of modern 20th and 21st century ground forces and a key part of combined arms combat.

Modern tanks are versatile mobile land weapons platforms whose main armament is a large-calibre tank gun mounted in a rotating gun turret, supplemented by machine guns or other ranged weapons such as anti-tank guided missiles or rocket launchers. They have heavy vehicle armour which provides protection for the crew, the vehicle's munition storage, fuel tank and propulsion systems. The use of tracks rather than wheels provides improved operational mobility which allows the tank to overcome rugged terrain and adverse conditions such as mud and ice/snow better than wheeled vehicles, and thus be more flexibly positioned at advantageous locations on the battlefield. These features enable the tank to perform in a variety of intense combat situations, simultaneously both offensively (with direct fire from their powerful main gun) and defensively (as fire support and defilade for friendly troops due to the near invulnerability to common infantry small arms and good resistance against heavier weapons, although anti-tank weapons used in 2022, some of them man-portable, have demonstrated the ability to destroy older generations of tanks with single shots), all while maintaining the mobility needed to exploit changing tactical situations. Fully integrating tanks into modern military forces spawned a new era of combat called armoured warfare.

A counterattack is a tactic employed in response to an attack, with the term originating in "war games". The general objective is to negate or thwart the advantage gained by the enemy during attack, while the specific objectives typically seek to regain lost ground or destroy the attacking enemy (this may take the form of an opposing sports team or military units).

A counter-offensive is a broad-scale counterattack. The counter-offensive is executed after exhausting the enemy's frontline troops and after the enemy reserves had been committed to combat and proven incapable of breaching defenses, but before the enemy has had the opportunity to assume new defensive positions. Sometimes the counter-offensive can be of a more limited operational maneuver nature, with more limited objectives rather than those seeking attainment of a strategic goal. A counter-offensive was considered by Clausewitz to be the most efficient means of forcing the attacker to abandon offensive plans. Counter-offensives can be executed not only on land, but also by the naval, and air forces. Strategic counter-offensives have been recorded by military historians in many wars throughout military history. Although not always known as such, because they are usually described by historians in conjunction with the defensive phase, such as the Battle of Moscow.

Line infantry was the type of infantry that formed the bulk of most European land armies from the mid-17th century to the mid-19th century. Maurice of Nassau and Gustavus Adolphus are generally regarded as its pioneers, while Turenne and Montecuccoli are closely associated with the post-1648 development of linear infantry tactics. For both battle and parade drill, it consisted of two to four ranks of foot soldiers drawn up side by side in rigid alignment, and thereby maximizing the effect of their firepower. By extension, the term came to be applied to the regular regiments "of the line" as opposed to light infantry, skirmishers, militia, support personnel, plus some other special categories of infantry not focused on heavy front line combat.

Army aviation is military aviation that is organized as a sub-branch under the command of an army, separate from a nation's dedicated air force. Army aviation units, sometimes described as air corps, are typically attached as a part of to a ground force and tasked to tactically assist its land warfare by providing close air support, rapid insertion, reconnaissance and logistics for front line ground operations. They usually comprise VTOL aircraft such as military helicopters, as well as gyrocopters, light fixed-wing attack aircraft and unmanned aerial vehicles (drones), and historically also aerostats such as military balloons and airships.

Prior to the establishment of separate national air forces, many armies had aviation units, which as the importance of aviation increased, were spun off into independent branches of the military. As the separation between a nation's ground and air forces led to a divergence of priorities, many armies sought to re-establish their own aviation branches to best serve their own organic tactical needs.

In a military context, the term front can have several meanings. According to official US Department of Defense and NATO definitions, a front can be "the line of contact of two opposing forces." This front line can be a local or tactical front, or it can range to a theater. An example of the latter was the Western Front in France and Belgium in World War I.

Relatedly, front can refer to the direction of the enemy or, in the absence of combat, the direction towards which a military unit is facing. Conversely, the term "home front" has been used to denote conditions in the civilian sector of a country at war, including those involved in the production of matériel.

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."