A textbook is a book used for studying a particular subject, often in schools or universities. It provides structured information, explanations, and examples to help students learn. Textbooks are usually organized into chapters, covering different topics within a subject, such as mathematics, science, or history. They often include exercises and questions to test understanding. Many textbooks are designed to align with specific curricula, making them essential tools for both teachers and students. They can be printed or available in digital formats, allowing for easy access. Some popular textbooks are written by well-known authors or experts in their fields, enhancing their credibility and usefulness.