QUESTION: How does Steemit reputation work?

Just found that Steemit platform has been updated recently.
So, as I see, there're several UI/UX improvements and new feature like reputation.

Does anybody know how it works right now? Is there any official release description?

Thanks in advance :)

P.S. Upvote in case you don't give a f*ck what means this reputation and how it's being calculated :D