Vp$IP 12.30 (15 out of 122) This is when the guy put money voluntary in the pot so this shows how often he plays hands. 12.30% Is not a lot, so when he limps or raises(puts money in pot) means he is playing tight and only plays good hands, so you should play back to him with good hands as well and if he starts to raise you better get out of his way because he could easily beat you pre flop, because pretty much AK AA KK are his range. Just think from 122 hands he was dealt he only played 15 of them so he is not putting money in pot with bad hands.
pfr 9.84 (12 out of 122) This is Pre flop raise. This means that when he entered pot he raised first. So from the 12.3% of his hands he plays 9.8% he open raised so he is playing tight and rarely limping with maybe pocket pairs to set mine.
won $ when when saw flop 41.67 (5 out 12) Self explanatory, basically when he saw the flop he won 41.67% of the time.
won $ at showdown 100.00 (1 out of 1) Well this means that he won a hand at showdown. But from 1 hand you really can't draw much of a conclusion. If he for example had like 80% (80 out of 100)won at showdown this would mean that he won 80% of the times at showdown so when he is interested in the pot he probably has a good hand because he wins 80% of the time and the other 20% when he lost could easily be you calling bad odds and catching you draws and getting like flush or straight over his two pair or set.
attempt to steal blinds 37.50 (6 out of 16) This means how many times he tried to steal blinds from like Button or Cut off. So basically he raised 6 hands out of 16 to try to pick up blinds. This would basically say that he steals only with good hands so if he had like 70% attempt to steal you then could 3bet him easily because most of the time he doesn't have anything and he just wants to pick up the blinds.
Well hope you understood everything, ask if something doesn't seem to be clear. Didn't really proofread so something might not make sense 
Also just search in videos for "HUD" Heads up display and there are a few videos that explain what stats are useful and what they mean.
and I see that stats are an important thing in online poker but I haven't figure out how can I interpret them.
