Solid-state lasers in welding are used in precision engineering, electrical engineering, electronics, and with the development of more powerful systems, also for welding thicker cross-sections, for example in automotive construction. The book discusses the special characteristics of welding with solid-state lasers, particularly Nd-YAG and Nd-glass lasers, and highlights the advantages and disadvantages compared to conventional welding methods. The use of optical fibers and the resulting benefits, such as in the application of robots, are also considered, along with the possibilities for quality assurance and process control. Metallurgy, the influence of surface layers, and the structural design of laser-welded joints are presented in detail. Additionally, the potential of less common methods, such as laser plastic welding and laser cladding, is also addressed.