3 Kinds of Books
There are a number of kind of books, but most of them can be classified into three: the guide, the advertisement, the thesis.
1. The Guide is purely informative and contains no argument whatsoever. Most descriptive writings, prose and poetry, fall into these. Legal instruction documents (not court arguments) are guides. Also included are manuals and handbooks. Some religious documents are also purely instructional. The "Why" question is neither anticipated nor answered.
2. The Advertisement. These are popular books that contain arguments based on personal or case experiences. They possess narratives in support of ideas. Like popular ads they may bear testimonials of celebrities or experts. These can be highly inspirational.
3. The Thesis. These are academic writings with lot of technical jargon written mainly for the academic audience. Includes research publications, academic articles, and contain technical arguments.
For instance, The Thesis is like work that forms the basis of the manufacture of a new smartphone. The Advertisement is how this phone is introduced to the public. The Guide is the manual that comes along with the phone on purchase.
Obviously, the advertisers play a significant role.