the first no gives u an idea, how many hands villian sees a flop with, second no tells how many hands they raise with pre. they suggest roughly villians preflop ranges. over a solid sample size it makes it easier to "put opp on a hand range". if you´re playing 6max u might add post flop AF, "went to sd" and "w$@sd" to rate their postflop play. mind that postflop stats need a way larger sample size, to be useful, personally i dont pay much attention to pre stats < 250 hands and post stats < 750 hands.

Don´t get too fancy when playing with HUD, there are still loads of more valuable info´s at the table than your HUD is showing.