The word "what is book" can be rephrased using numerous synonyms. For instance, you can ask, "What is literature?" or "What is a publication?" or "What is a tome?" or "What is a manuscript?" or "What is a printed work?" or "What is a novel?" or "What is a text?" These synonyms refer to written or printed materials that are bound together, containing various texts that can educate, entertain, and inform readers. Books are diverse and can vary in topic, length, and genre. From fiction to non-fiction, books have remained an excellent source of knowledge and art that we can pass down to future generations.