Amazingly confirms the wave particle duality of quantum mechanics.
This experiment seems to be really hard to do, and so there aren't many super clear demonstration videos with full experimental setup description out there unfortunately.
Wikipedia has a good summary at: en.wikipedia.org/wiki/Double-slit_experiment#Overview
For single-photon non-double-slit experiments see: single photon production and detection experiments. Those are basically a pre-requisite to this.
It would be amazing to answer this with single particle double slit experiment measurements!