Not everything that is learned is contained in books. As it appears, it can be learned in the classroom, from social life or from other people's experiences. The teacher who gives us a rich knowledge and some information which are not in books. From this point of view, it is the wise people who share knowledge with others and, apparently, what other people share; to some extent, it is not contained in books. In the same line with this, the teacher, as the source of knowledge in the classroom, shares ideas, thoughts, and knowledge which is not contained in books. And, the teacher transmits it from his or her own experience.