Direct fire

Direct fire or line-of-sight fire refers to firing of a ranged weapon whose projectile is launched directly at a target within the line-of-sight of the user.^[1] The firing weapon must have a sighting device and an unobstructed view to the target, which means no obstacles or friendly units can be between it and the target. A weapon engaged in direct fire conversely exposes itself to direct return fire from the target.^[2]

This is in contrast to indirect fire, which refers to firing a projectile on a curved ballistic trajectory or delivering self-accelerated munitions capable of long range and various degrees of homing abilities to alter the flight path. Indirect fire does not need a direct line-of-sight to the target because the shots are normally directed by a forward observer. As such, indirect-fire weapons can shoot over obstacles or friendly units and the weapons can be concealed from counter-battery fire.