Sentence:  "Where they burn books, they will also burn people" is a famous <WSD>quotation</WSD> from Heinrich Heine. 
Meaning of the word marked with <WSD> tags:  A fragment of a human expression that is repeated by somebody else. Most often a quotation is taken from (literature) or (speech), but also scenes from a (movie), elements of a (painting), a passage of music, etc., may be quoted.