An affirmative minor establishes inclusion of the minor term under the middle. A universal major states what holds, or fails to hold, for every member of that middle. Together these yield a relation between minor and major.
Affirmative major: the major term is affirmed of all the middle, so the conclusion is affirmative.
Negative major: the major term is denied of all the middle, so the conclusion is negative.
The quantity of the conclusion tracks the minor: a universal minor gives a universal conclusion; a particular minor gives a particular one.