A precision-guided munition (PGM, smart weapon, smart munition) is a guided munition intended to precisely hit a specific target, and to minimize collateral damage.
Because the damage effects of explosive weapons decrease with distance, even modest improvements in accuracy (hence reduction in miss distance) enable a target to be attacked with fewer or smaller bombs. Thus, even if some bombs miss, fewer air crews are put at risk and the harm to civilians and the amount of collateral damage may be reduced.
The advent of precision-guided munitions resulted in the renaming of older bombs as "gravity bombs", "dumb bombs", or "iron bombs".
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