Concise, lots of info, with what seems like enough detail to me. I use the book in homeschooling. My son is 8 and the book works okay. It is just brief enough to make him not despair when we start on a new section. We take turns reading paragraphs. Usually he finds the 1-2 page pieces interesting enough to want to look in other books for additional information or comparisons. It's a bit dry, pure text, no pictures, well suited as summarized info. The book seems intended for older ages though, say teens and up.