The word "laser" actually stands for Light Amplification by Stimulated Emission of Radiation. The light from a laser is coherent, meaning that all of the wavelengths are of uniform size and are in phase with each other.
Lasers have had wide use in manufacturing, for measuring tolerances, the military, as a guide for weapons (and as a weapon itself) medicine, as a scalpel, communications, retail, and sound reproduction, to name a few. (The CD player uses a low power laser to read the "bumps" on the CD and transmit them into sound. Consumer items possessing a bar code are passed by the checkout where the code can be read by a laser.)
Since its invention in 1958, it has become a widely used and flexible tool. See more at the link: