well, a quick rundown on modes:
Ionian
Dorian
Phrygian
Lydian
Mixolydian
Aeolian
Locrian
Ionian is your standard scale, like C: C D E F G A B C
Dorian is a scale that you base off the second in the root scale
So, a C Dorian would be: D E F G A B C D
Continue that with Phrygian (based off of the third): E F G A B C D E
and so on. Aeolian, which is based off the sixth, is what's known as a relative minor, because it's the same scale as that minor key
A C Aeolian, then, ( A B C D E F G A ), is the same as an A minor scale
did i explain that clearly?