on any thread that you start , you have the chance to thank only one of the reply posts ,on doing this it gives that member "3 points"  you only can do it  once in that thread ,(so choose wisely )

on all posts by other members in any thread  you have the option of    giving them 1 point by clicking on the "+" in the right hand side of that post if you think there post deserves it ,

The "-" vote is disabled and does not take away any points

These points are displayed under your avatar

This system was already running when I took the forum over , I just thought it was better explained