This book is a short guide to the basic commands of the Linux operating system. The reader will find in it a description of most of the commands he needs in his daily work. The first chapters provide the most basic information about working with the system. As you read the book, the material becomes more complex; having mastered it, the reader will be able to solve quite serious problems. Beginners just starting to learn Linux will find information about the commands they need most. But the intended audience is not limited to newcomers. The material in the book will also remind experienced users of commands and options that they have forgotten or that, for some reason, they have not previously paid attention to.