The book or book is on many subjects. Books on subjects like mathematics, science, language, biography etc. are available in the market. Books also come for entertainment. Books like novels, comics etc. are full of entertainment in these. Some books are full of literary knowledge. It contains a wonderful collection of poems, prose, stories. Be it engineering or medical studies, the book is always available for knowledge. Thick books on various subjects have to be read in college studies. Books are also helpful in preparing for competitive exams. The mind and soul get peace by reading religious books. The Constitution of our country is also present in the form of a book. We have got the knowledge of the history of the world only through the book. The historical facts written in the books are preserved even today. It can also be said that a book is the best way to secure knowledge. What was human life like in olden times? Which country was ruled by which king? What was the social environment like in ancient times? What were the ideas and inventions of a great philosopher, scientist ? We find answers to all these questions in books. In the book, the knowledge of that time is obtained in which we are not present in the time or period. A book is a mirror of the author's imagination, emotion and knowledge. Through the book, the author spreads the light of knowledge. The author who wrote the book also goes away from the world but the book remains forever. The book immortalizes the name and work of any author. Great philosophers and litterateurs like Aristotle Shakespeare have left the world but their work is still alive in books. In olden times the book was handwritten as there was no facility of printing then. Writers used to put knowledge on the page with the help of a pen. At that time, copper plates or bhojpatras were used for writing. Less books were written in those days. Most of the knowledge exchange took place by speaking and by memorization. Nowadays, books of many authors are available on almost every subject. There is no restriction of language in books.