Non fiction books

I am learning to describe the features of a non-fiction text.

The book ‘The Biggest Land Animal” is a non-fiction text. I know it is non-fiction because:

Photos What type of pictures are in this book?	True photos
Index What does the index tell us?	The page numbers to find what you want to read.
Glossary What does the glossary tell us?	It tells us what the words are in the book.
Why do we read non-fiction books?	So we about things.
What have you learnt from reading this book?	About elephants.

It was a little bit hard to talk about non fiction books because I don't know how to describe them very well. I get some of my words mixed up with Korean words.