What Does It Mean When a Book Has Good World Building?

When a book is described as having good world building, it usually means the author has put a lot of effort into intricately imagining the world down to like the smallest details. A really popular example of this is Lord of the Rings because Tolkien thought up,. you know, races and their languages and their histories in like every imaginable detail. Bria: I find that it has to be pretty gradual for me, like too much info up front and I'm, I am out. She says she likes books that are very similar to our own, but with one little difference.