The rating system is pretty standard across many websites, but in case you’d like clarification, here’s how it goes here:

0 stars: Did not finish (hasn’t happened yet!)
1 star: I really did not like it at all
2 stars: Somewhat decent. For the most part I didn’t enjoy it, but it had some sweet spots
3 stars: Decent. Didn’t love it, didn’t hate it
4 stars: Very good, enjoyed almost all of it
5 stars: I loved every second of it.

A five star rating does not necessarily mean it’s one of my all-time favorite books, it may only mean that I found the story very enjoyable.