The book "Calculus" is a foundational mathematical text that explores the principles of differentiation and integration, offering a comprehensive understanding of how functions change and accumulate quantities. It begins by introducing the concept of derivatives, which measure rates of change in functions, and provides rules and applications for finding derivatives, making it an essential tool for analyzing curves and solving real-world problems in fields like physics, engineering, and economics. The book also delves into integration, the reverse process of differentiation, which focuses on finding areas, volumes, and accumulated quantities. It illustrates how the Fundamental Theorem of Calculus connects these two fundamental concepts. Overall, "Calculus" is an integral resource for students, scientists, and mathematicians seeking to master the core principles of this critical branch of mathematics and apply them to a wide range of practical scenarios.