Lasers are devices that emit light through a process called stimulated emission. They produce a highly focused beam of light that can be used in various applications, from medical procedures to cutting materials. The unique properties of laser light, such as coherence and monochromaticity, make it distinct from regular light sources. There are several types of lasers, including solid-state lasers, gas lasers, and semiconductor lasers. Each type has its own specific uses and advantages. For example, CO2 lasers are commonly used in industrial cutting, while diode lasers are often found in consumer electronics like DVD players.