The textbook provides information about the origin and about the main stages of development of one of the first, and today one of the most common technological processes of welding materials. A brief information about the main types of welding energy sources used for obtaining permanent connections about the physical nature of the welding processes. Examples of equipment required to implement various technological operations. Modern problems of welding science and technology. Designed for students directions 15.03.01 mechanical engineering, 12.03.05 "Laser engineering and laser technologies and specialty", 15.05.01 "Design of technological machines and complexes", may be useful to students of lyceums, colleges, vocational schools and technical schools, as well as a wide range of readers to discover the fundamentals of welding technology.