* "Effected" is the past tense and past participle of the verb "to effect," meaning to bring about or cause something. For example: "The new policy effected a significant change in the company's operations."
* "Affected" is the past tense and past participle of the verb "to affect," meaning to influence or impact something. For example: "The hurricane affected the coastal region."
So, which one is right depends on the context!