What is Light?

As someone with a high degree of interest in quantum physics—as a lay person and certainly not as a scientist—I’ve always been fascinated by the double slit experiment (video) and how matter and energy can display characteristics of both waves and particles in what is known as the wave–particle duality.

Is light a bunch of particles like we’ve come to believe (think “photons”)? Or is light a frequency wave (think the “electromagnetic spectrum“)? 

I came across the video below that demonstrates the properties of light, using the double slit experiment, with “real” people on the street. Usually these videos belittle people and their lack of science knowledge, but this one was done in the spirit of fun, being informative, and truly showing how light behaves. (via HighT3ch)