Textbook

A textbook essentially presents the foundations of a given discipline in accordance with that discipline's current level of development. It is a book of instructional literature. Textbooks exist for every level and every type of education, including self-education. They are an indispensable educational tool and as such contribute to fulfill the educational requirements of a population. They are nevertheless often conservative, socially and politically, because they usually convey the established values of a given society and can be a hindrance to social progress. In some cases they are frankly biased.