Question: What is the difference between a laser and a beam of light

Mossy answered on 9 Nov 2018:

Oh man – best question ever!!! There are a few “cosmetic” differences. Like…lasers tend to go in one direction but lights go in all directions. Lasers tend to be one colour but light is made up of different colours. But those aren’t the real difference.

The real difference is coherence. All light (light bulbs, flames, lasers) are made up of light waves. So when you look at a light bulb – you are seeing loads and loads of waves hitting your eye.

The difference between a laser and a light – is that in a laser…all the waves vibrate up and down at the same time, but in a light – all the light waves are bouncing up and down randomly. It’s called coherence!