A cluster munition, or cluster bomb, is a large canister containing between a dozen and a few hundred submunitions, each the size of a drink can.

Cluster munitions can be dropped from the air (fighter planes, helicopters...) or launched from the ground (artillery, combat vehicles, rocket launchers...). The container opens in mid-air and scatters its submunitions over a wide area (sometimes up to several hectares). In principle, the submunitions are designed to explode on impact, either when they hit the ground or the target.

These weapons aim to saturate and prevent access to an area in which one or more targets have been located (infrastructure, vehicles, troops ...), according to a specific objective (blocking the passage or the stationing of troops or armored units, putting them out of action, or destroying a military target).

Cluster bombs can be dropped from aircraft or fired from the ground. They are designed to break open in mid-air, releasing the submunitions and scattering them over an area that can be as big as several football fields.

When the submunitions explode, they fire hundreds of fragments of metal that travel at the speed of a bullet. Anybody within the area, military or civilian, is very likely to be killed or seriously injured. Unlike landmines, which are designed to maim rather than kill, cluster bombs are much more likely to kill and to cause multiple casualties. Even if a victim lives they will suffer various injuries such as loss of limbs, burns, ruptured ear drums, blindness and internal complications.

The following sequence shows what happens when a cluster bomb is dropped from an aeroplane.