favorable influence; positive effect
Used for a beneficial impact on someone or something, often in formal or written contexts.
His advice had a favorable influence on my career.
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.
好影響 describes a favorable or positive influence, the direct opposite of the harmful influence meant by 悪影響.
Compound of 好 (good, favorable) and 影響 (influence, effect).