RPG launcher

A rocket-propelled grenade (often abbreviated RPG) is a shoulder-fired anti-tank weapon system that fires rockets equipped with an explosive warhead. Most RPGs can be carried by an individual soldier. These warheads are affixed to a rocket motor which propels the RPG towards the target and they are stabilized in flight with fins. Some types of RPG are reloadable with new rocket-propelled grenades, while others are single-use. RPGs, with some exceptions, are generally loaded from the muzzle.

RPGs with high explosive anti-tank warheads (HEAT) are very effective against armored vehicles such as armoured personnel carriers (APCs). However, heavily armored vehicles from the 2010s, such as main battle tanks, are generally too well armored (with thick composite and/or reactive armor) to be penetrated by an RPG, unless less armored sections of vehicle are exploited. Various warheads are also capable of causing secondary damage to vulnerable systems (especially sights, tracks, rear and roof of turrets) and other unarmored targets.

The term "rocket-propelled grenade" is, strictly speaking, a backronym; it stems from the Russian language РПГ or ручной противотанковый гранатомёт (transliterated as "ruchnoy protivotankovy granatomyot"), meaning "hand-held anti-tank grenade launcher", the name given to early Russian designs.

The static nature of trench warfare in World War I encouraged the use of shielded defenses, even including personal armor, that were impenetrable by standard rifle ammunition. This led to some isolated experiments with higher caliber rifles, similar to elephant guns, using armor-piercing ammunition. The very first tanks, the British Mark I, could be penetrated by these weapons under the right conditions. Mark IV tanks, however, had slightly thicker armor. In response, the German rushed to create an upgraded version of these early anti-armor rifles, the Tankgewehr M1918, the first anti-tank rifle. In the inter-war years, tank armor continued to increase overall, to the point that anti-tank rifles could no longer be effective against anything but light tanks; any rifle made powerful enough for heavier tanks would exceed the ability of a soldier to carry and fire the weapon.

...
Wikipedia