Since the occurrence of the first LASER (Light for Amplification by Stimulated Emission of Radiation) in the year 1960, there has been a steady increase in its Application. Different types have been found. There is rarely any scientific field which is not influenced by laser technology. As the capability of lasers increased, its applications became more and more diverse. Because of this laser, man work has become simple. Without  any hard work, very fastly work can be finished. In this chapter, we enumerate a few types of lasers with its advantages and disadvantages and then go on to discuss more details about its applications in various fields.