Here is a brief description of medals, which are tied to points: https://opengameart.org/content/medals

Here is a detailed list of all the medals and how to obtain them: https://opengameart.org/comment/55632#comment-55632

There are not any tangible prizes for points. They're just for the prestige. Though people with more points tend to be respected quite a bit. Not sure if that's a cause/effect relationship or if the people who tend to be frequent participants in this community (i.e. "pillars of the community") tend also to earn a lot of points as a side-effect. :)

Let me know if this does not address your questions. :)