Textbooks: A book used in schools or colleges for the formal study of a subject. Another word we can say 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 and increasingly in scanned format in P2P networks. Handbooks: A handbook is a type of reference work, or other collection of instructions, that is intended to provide ready reference. It is mostly used for research purposes.