A textbook or coursebook is a manual of instruction in any branch of study. Textbooks are produced according to the demands of educational institutions. Although most textbooks are only published in printed format, many are now available as online electronic books

E-book

An electronic book is a book-length publication in digital form, consisting of text, images, or both, and produced on, published through, and readable on computers or other electronic devices. Sometimes the equivalent of a conventional printed book, e-books can also be born digital...

 and increasingly in scanned format in P2P

Peer-to-peer

Peer-to-peer computing or networking is a distributed application architecture that partitions tasks or workloads among peers. Peers are equally privileged, equipotent participants in the application...

 networks.
The ancient Greeks

Ancient Greece

Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...

 wrote texts intended for education. The modern textbook has its roots in the standardization made possible by the printing press.