This lecture covers the principles and distinctions of Selective Laser Sintering and Melting (SLS and SLM), including the consolidation process, equipment, and materials used. It explains the advantages of SLS and SLM, such as fast processing, material versatility, and geometric complexity. The lecture also delves into the mechanical properties of parts produced by these processes, as well as their applications in prototyping, small series production, and industries like aerospace and medicine.