If you're genuinely interested, the best video I've seen, from a highly respected researcher, is this one I've linked to below.
It's 3 and a half hours, but the first two hours are the most informative.
If it's TL;DR, then I'm happy to try to explain what little I know if you have any questions.
https://www.youtube.com/watch?v=7xTGNNLPyMI