What is the difference between 책 and 책자? In my Korean textbook, there is one sentence as follows: 안내 책자, 생활 정보지, 인터넷, 외국인 지원센터 등 여러 가지가 있을 것이다. I wonder why 책자 was used instead of 책 in 안내 책자? Thank you so much in advance.