First of all, let's start by explaining what exactly mixing and mastering is. The first term, mixing, refers to the process of putting multiple layers of audio together to make one final track, or to musically modify an existing track.
The second term, mastering, refers to the process of optimizing the final track using all sorts of different mastering elements such as compression, equalization, stereo enhancement and more.

AAMS does the Mastering part very well and improves Mixing skills!
Recommended Here, I am a AAMS user for 8 years now.

Michael