A laser is a light source that emits light amplified through the stimulated emission of photons. The acronym, LASER, actually stands for Light Amplification by Stimulated Emission of Radiation. Lasers come in many shapes and sizes. Some can fit in your pocket, and some are huge and take up entire rooms. Some emit pulses of light, while others emit continuous beams of light. Since there are so many types of lasers, it’s not surprising that they find wide-ranging applications from simply pointing at a screen during a presentation to carrying out complex measurements in physics and chemistry experiments.