A laser is a machine that makes an amplified, single-color source of light. It uses special gases or crystals to make the light with only a single color. The gases are energized to make them emit light. Then mirrors are used to amplify (make stronger) the light.
A laser can be made so all the light travels in one direction, so the energy of the light stays as a narrow beam of collimated light that does not spread as much as in a flashlight (electric torch). This narrow beam makes a single point of light.
The word "laser" is an acronym for "light amplification by stimulated emission of radiation".[1][2] Both the device and its name were developed from the earlier Maser.