We say it is monochromatic. We call this organization coherence. That means that the light is of the same wavelength and perfectly in phase. We say that it is collimated. The average laser beam will spread approximately one meter in a distance of one kilometer.
Some laser beams spread only a few centimeters over a distance of one kilometer.
Some laser beams spread only a few centimeters over a distance of miles with the help of more sophisticated lens system. When the laser was invented, it was seen by many as a fascinating oddity, a product of pure research in search of a practical use. Its characteristics, however, guaranteed that the search would not be a long one. The average intensity of a continuous 1 mw laser is about the intensity of sunlight on a clear day. Lasers may put out their light continuously or in very short, very intense bursts of power.