What is the phenomenon of light pillars?

<p style=";text-align:left;direction:ltr">Light Pillars are luminous streaks that usually appear vertically in the sky near the Earth&#39;s surface, and are a stunning optical phenomenon, which occurs when layers of ice crystals form in the lower atmosphere over an artificial light source located on the Earth&#39;s surface such as street lights, or a light source. Natural light such as moonlight, and these crystals are often arranged in flat hexagons, becoming like mirrors that reflect light between them, creating this effect of light columns in the night sky, and the larger the size of the crystals, the more pronounced this effect. More</p>