noun
favorable influence; positive effect
Used for a beneficial impact on someone or something, often in formal or written contexts.
彼の助言は私のキャリアに好影響を与えた。
His advice had a favorable influence on my career.
規則的な運動は健康に好影響を及ぼす。
Regular exercise has a positive effect on health.
影響 is the neutral term for 'influence' or 'effect', while 好影響 specifies a favorable one.
Compound of 好 (good, favorable) and 影響 (influence, effect).