read the diary of anne frank and explain about the areas of concentration camps in not more than 200 words.
Well, first of all, I believe you are supposed to read the book yourself - and you should - the length is deceptive, it is actually a very quick and easy read.
That said, you must realize that unlike Night (Elie Wiesel) for example, this holocaust book is a diary written during the time Anne Frank was in hiding. Although she and her family were found at the end (and Anne presumably died in a concentration camp), the diary holds no first-hand knowledge of what concentration camps were like.
The diary does do a good job however, of explaining the fear of getting caught and sent to one. She knew the things happening to Jews were unthinkable and that once they went in they didn't come back out. They did receive news reports on a radio - so they were aware of as much as the media was reporting (which we know now wasn't much). She also experienced the hatred and separation of the Jews within her hometown at the beginning of the diary - so she logically assumes the concentration camps were an extension of this hatred.
I would guess your teacher wants you to answer this question based as much on prior experience and personal knowledge as she does on actual information in the book.