"Affection" is a feeling or emotion, usually of fondness (if you are fond of somebody, you have an affection toward/for them) "Effect" is a result, as in "cause and effect." If I do not study, I will do poorly on my test. There is also a verb "to affect," which means "to have an effect on someone or something." Watching too much TV will affect my eyes in a bad way." And a verb "to effect," but this is not as common. It means "cause to happen."