Well, usually when we say 'novel', we mean a fictional story of some length. If 'The Thief' fits that description, it's a novel and thereby also a book. But if it's a non-fiction account or something else, it might just be a book in a broader sense.
The Book Thief is an amazing novel. It manages to be both tragic and beautiful at the same time. The descriptions of the settings, like the small German town, are so detailed that you feel like you're there. The relationships between the characters, such as Liesel and her foster father, are complex and full of emotion.
The Book Thief is an extraordinary novel. It's a story that shows the power of words during the harsh times of Nazi Germany. The characters are vividly drawn, especially Liesel. Her love for books in such a dark world is really inspiring. The narrative style, with Death as the narrator, gives a unique perspective on the events.
It is fiction. The story is a work of the author's imagination, set in Nazi Germany, and it tells a very moving and poignant story about a girl and her experiences during that dark time, but it is not based on a true story in a literal sense.
It's fiction. The story is a work of the author's imagination. However, it does a great job of painting a vivid picture of life during the war. The main character, Liesel, and her experiences are fictional, but they give readers an idea of what it might have been like for ordinary people in Nazi - occupied Germany.