How can the topic of "books" connect to the deeper historical topic of the Holocaust and the cruelty presented in "The Book Thief"?

The books represent language..... Liesel's knowledge and her ability to communicate through the written (and read) word. The book burning represented censorship..... the manipulation of the populace, the decision of what they can and cannot read.... the information they are allowed to have. The book Liesel retrieves (steals) from the burning is an act of defiance..... she isn't going to accept propaganda.