Laser Welding Technology includes components, systems, machines and customer-specific systems for laser welding. In laser welding, the heat required to connect the parts is generated by a laser beam focused on the seam. Neighboring processes are electron beam welding and light radiation welding. Laser is an acronym: Light Amplification by Stimulated Emission of Radiation. CO2 gas lasers, Nd: YAG solid state lasers, and increasingly diode lasers are common laser sources. While CO2 lasers are used in the high-performance range of material processing, solid-state lasers and diode lasers are used for the fine welding of metals and for the welding of plastics. For welding metal parts, the laser beam directly melts both parts at the center of the weld. Necessary components of the Laser Welding Technique are the laser beam source, the beam guidance system, the focusing optics, a movement system for the representation of the seam course as well as the control. Laser Welding Technology is used both for welding metal parts and thermoplastics. In both cases it is possible to connect different materials. Almost all seam shapes can be welded to metal parts such as butt seams, fillet welds or fillet welds in a lap joint. Laser Welding allows a high welding speed as well as narrow welding seams with low thermal distortion.