"Computer networks" is a book that has become a bible for everyone interested in computer science and communication technologies. It examines in detail the basic concepts, principles of construction, architecture and protocols of computer networks. The authors explain how to properly configure a network connection, ensure data security, and optimize network performance. The book "Computer networks" will help the reader understand the principles of the Internet, LAN and WAN networks, VPN, wireless technologies. The authors provide numerous examples and exercises that will help consolidate the acquired knowledge and skills. Thanks to accessible speech and a clear structure, the book is suitable for both beginners and experienced specialists in the field of IT. "Computer networks" is not only a source of professional information, but also an inexhaustible source of inspiration for further self-improvement in this interesting field.