Main Entry: 1af·fect
Pronunciation: 'a-"fekt
Function: noun
Etymology: Middle English, from Latin affectus, from afficere
Date: 14th century
1 obsolete : FEELING, AFFECTION
2 : the conscious subjective aspect of an emotion considered apart from bodily changes
usage see EFFECT
Main Entry: 1ef·fect
Pronunciation: i-'fekt, e-, E-
Function: noun
Etymology: Middle English, from Middle French & Latin; Middle French, from Latin effectus, from efficere to bring about, from ex- + facere to make, do -- more at DO
Date: 14th century
1 a : PURPORT, INTENT b : basic meaning : ESSENCE
2 : something that inevitably follows an antecedent (as a cause or agent)
3 : an outward sign : APPEARANCE
4 : ACCOMPLISHMENT, FULFILLMENT
5 : power to bring about a result : INFLUENCE <the content itself of television ... is therefore less important than its effect -- Current Biography>
6 plural : movable property : GOODS <personal effects>
7 a : a distinctive impression <the color gives the effect of being warm> b : the creation of a desired impression <her tears were purely for effect> c (1) : something designed to produce a distinctive or desired impression -- usually used in plural (2) plural : SPECIAL EFFECTS
8 : the quality or state of being operative : OPERATION <the law goes into effect next week>
- in effect : in substance : VIRTUALLY <the ... committee agreed to what was in effect a reduction in the hourly wage -- Current Biography>
- to the effect : with the meaning <issued a statement to the effect that he would resign>
Dictionary
[Edit]: On a really basic level, affect is for things pertaining to emotions, things like that, and effect would be for 'special effects' and things like that.