To get German degrees of Kh which is what most of us here are familiar with, divide the ppm by 17.9 to get degrees of hardness. Same goes for converting Gh ppm figures..
Alkalinity and buffering capacity are Kh aka "carbonate hardness". Gh is the measure of dissolved minerals, primarily calcium and magnesium.
Your Aqualab test measures Kh. 120ppm=roughly 6.7 degrees Kh