Throughout this article, there are simple and complex versions of most of the physics. If you are new to the subject, you might like to just read the simple version or only skim the complex version. If you are comfortable with the basic ideas, then the complex versions are more exact. The physics of lasers is quite complicated so the real story is harder to understand than the most general ideas. The light we see is usually a mixture of all the different colors of light, bouncing off objects around us and eventually ending up at our eyes.
Laser light is quite different for a few reasons.
The most important are listed below and for each one, there is a simplified version of the properties of lasers and then a more exact but more complex version. If we split up white light, we can see all the colors of the rainbow but if we try to split up laser light, we find there is nothing except the single laser color. Light from a bulb or most other sources of light spreads out in many directions. Laser light is quite different in that all the light is directed the same way. Beams of laser light can be extremely tight over quite long distances.