Answer:
This is because the Nazis which ruled Germany did this .They first started with the burning of the books which contained the rich culture and tenets of the country under the guise of cleansing the country.
They then started burning the people who were mostly Jews during the holocaust in which Adolph Hitler was in charge. This explains the meaning of the burning of the books and a big emphasis is placed to avoid a reoccurrence due to the bitter experiences and memories it left on the people.