The book “Ordinary Differential Equations” by Sergey Petrov is a fascinating and deep immersion in the world of mathematical analysis, which will become a desktop manual for both students and professionals working in the field of science and technology. This work stands out among other textbooks on differential equations due to its accessible style of presentation and practical approach to complex topics. From the first pages of the book, the reader finds himself on an exciting journey, where ordinary differential equations become the key to understanding the many phenomena occurring in the world around him. Petrov not only expounds the theory, but also demonstrates how these mathematical constructs are applied in real life from physics and engineering to biology and economics. Each section of the book is riddled with examples that make the material more visual and understandable, and also help the reader to see how abstract formulas come to life in practical tasks. Who can like this book? First of all, it will be of interest to students of technical and natural sciences who study mathematics at a deeper level . However, not only students will find useful information in it. Engineers, physicists and even economists working with models and forecasts will be able to extract a lot of useful from the methods proposed in the book. Even those who are just interested in mathematics and want to expand their knowledge will find here a lot of fascinating facts and ideas. The topics raised in the book cover a wide range of issues, ranging from the foundations of the theory of ordinary differential equations to complex problems that require a creative approach to solving. Petrov considers both linear and nonlinear equations, explaining in detail the methods of their solution and application. It focuses on such important aspects as the sustainability of decisions, qualitative analysis and numerical methods, which makes the book relevant for the modern reader. Sergey Petrov's style is distinguished by clarity and logic. It skillfully combines theoretical calculations with practical examples, which allows the reader not only to understand, but also to apply the knowledge gained. Petrov is the author of several well-known works in the field of mathematics and physics, and his experience is reflected in every paragraph of this book. He is able to explain complex things in simple language, which makes his works available to a wide audience. The book “Ordinary Differential Equations” may also be of interest to those who are looking for alternative sources of information on mathematics. Readers who are already familiar with works such as "Differential Equations and Their Applications" or "