As far as I know, they're just ordinary fake Internet points, that is, its meant to represent a sort of reputation system, where more active / helpful members have more points. I imagine its meant to help users determine who to trust in the case of multiple conflicting answers, but Twine is simple enough that you can generally try each answer yourself anyway, and the community is small enough that you can probably get a sense of who knows what they're doing (and who doesn't) just by poking around, regardless of points. This whole Q&A system is based on an open source implementation of Stack Exchange, so you can look at their docs for more info.