The book "Ordinary Differential Equations" by the authors B. and . Arnold and Y. C. Ilyashenko is not just a textbook, but a real find for everyone who seeks to understand more deeply the world of mathematical analysis and its applications. This work, written by outstanding scientists, is a comprehensive and systematic approach to the study of ordinary differential equations (ODIs), which play a key role in mathematics and its applications in physics, engineering, biology and many other fields. The book covers a wide range of topics ranging from basics to more complex concepts such as sustainability solutions and qualitative analysis of dynamic systems. The authors offer the reader not only theoretical calculations, but also practical examples, which makes the material more accessible and understandable. In this work you will find not only formulas and theorems, but also deep reflections on the nature of mathematical models that describe real processes in the surrounding world. This book will be of interest to both undergraduate and graduate students, as well as teachers and practitioners working in the field of exact sciences. If you study mathematics, physics or engineering disciplines, the “Ordinary Differential Equations” will be an indispensable tool for you. It is suitable for readers with different levels of training - from those who are just starting to get acquainted with ODU, to those who want to deepen their knowledge and skills. The topics raised in the book cover not only mathematical theory, but also its practical application. The authors explore such important issues as the existence and uniqueness of solutions, methods of finding them, as well as stability and oscillatory processes. These aspects make the book particularly valuable for those involved in modeling and analyzing dynamical systems in various fields of science and technology. Arnold and Ilyashenko's writing style is clear and logical. They are able to explain complex concepts in a simple and accessible language, which makes their work not only a textbook, but also a fascinating reading. In. and . Arnold, known for his work in mathematics and mechanics, as well as his colleague Yu. C. Ilyashenko, made a significant contribution to the development of the theory of differential equations. Their joint work is the result of many years of research and practical experience, which gives the book special value. If you are looking for literature that will help you not only to master the theory, but also to learn how to apply knowledge in practice, then “Ordinary Differential Equations” is what you need. This book will be your reliable companion in the world of mathematics, opening up new horizons and opportunities for you. You will be able not only to solve problems, but also to better understand how mathematical models work in the real world. In conclusion, “Ordinary Differential Equations” is not just a book, but a whole world worth diving into. It inspires the study and discovery of new knowledge, and also helps to develop analytical thinking. If you want to become a master in mathematics and learn how to apply your knowledge to real-world problems, this book is your first step towards success.