ELI5 Olive Oil - virgin, extra-virgin & refined - what's the difference?

What else determines the quality of olive oil and what's the difference between extra virgin, virgin, and refined olive oil? How is olive oil extracted? What are the proven health benefits of consuming olive oil? ... we explain like I'm five Thank you to the r/explainlikeimfive community and in particular the following users whose questions and comments formed the basis of this discussion: probbablyacantolope, frommerman, gcarsk, natureman123 & attackads To the ELI5 community that has supported us so far, thanks for all your feedback and comments. Join us on Twitter: https://www.twitter.com/eli5ThePodcast/ or send us an e-mail: [email protected]