One of the most heavily used types of non-fiction writing is the textbook! While students everywhere may sometimes despise the existence of textbooks, they are, in many ways, the blocks on which our education is founded!
Defined in the most basic way, textbooks are books of thorough information about a branch of study. Usually created for an educational institutions, there are also textbooks created for the at-home learner.
Textbooks are also a huge source of non-fiction writing because of the incredibly wide variety of topics that they cover: math, physics, anthropology, English, literature, language and more. There are textbooks that cover nearly ever thing you could possibly want to learn more about, you just have to find it!