What's QoS and how does it affect aion latency?

Well, i've managed to find a secure program (Ashampoo internet accelerator 3), and there's one option that made me pretty interested the QoS.
Well, atm i'm using it and 20% of my internet is reserved for it, it says that's for important package, well, my doubts are:
Will that lower my ping ?
How does that work ? (just curiosity)
Should i lower it or increase it ?

 

It won't do you much good. QoS doesn't decrease the time your packets take to get there, but it increases priority to selected packets when your network is congested. Typically, your router is the best option for QoS, but most router QoS firmware is crap, you should download custom router firmware. If you really need QoS.

Edit: I wrote that when I was high. How..

 

Well then, then i'll just disable it.