Learn in the textbookRisk Management and Response Strategies
DefinitionMitigation (軽減) is the response that keeps the cause of a risk but lowers its probability or reduces its impact when it happens.
ExplanationLowering probability is prevention that works before the event, and reducing impact is preparation that limits damage afterward; both count as mitigation. Both cost money, so you compare the expected drop in loss with the cost of the measure to decide how far to go. Unlike avoidance the cause remains, so you keep watching the leftover risk after acting.
AnalogyIt is like servicing your bike so it is less likely to break down and wearing a helmet so a fall hurts less. You have not given up riding.
Memory hookMitigate comes from a Latin root meaning "to soften": the blow still lands, just more gently. Avoidance means it never lands at all.