Cutting with lasers is accomplished with carbon dioxide (CO2) and neodymium: yttrium-aluminum-garnet (Nd:YAG) lasers. This article provides a description of the process variables and principles of laser cutting. It discusses the three basic types of CO2 gas lasers, namely, slow axial flow, transverse flow, and fast axial flow and reviews the applications of Nd:YAG laser. The article describes the basic parameters in the laser-cutting process: beam quality, power, travel speed, nozzles design, and focal-point position. Several material conditions that affect the quality of the laser cut are also discussed. The article provides information on the basic laser-cutting system and its optional equipment. A general description of how well each metal group can be cut is also provided.