Both selective laser sintering (SLS) and selective laser melting (SLM) are laser powder bed fusion. This chapter provides working of SLS and SLM and the role of their various parameters. Fabrication speeds due to these processes are low which is one of the drawbacks of additive manufacturing; this chapter provides various methods to increase the speed. It is reasoned why there are only two binding mechanisms (liquid phase sintering and full melting) instead of four (liquid phase sintering, full melting, solid state sintering and chemical-induced binding) in laser powder bed fusion. Application of the process in the repair of a 3D part, though not commonly practiced, is given.