To culinary experts and to the average person the term “Extra Virgin” has a ring of exclusiveness and quality to it. When it comes to olive oil, exactly what does this term signify?

I am supposed to explain the chemistry behind Extra Virgin Olive oils, what makes the difference between olive oils, and why one type perhaps healthier, better tasting, etc. than another is. Do you get what you may be paying for?

Not sure about explaining the chemistry part. But I import and sell olive oil from Spain. Extra virgin and virgin oil is essentially a physical cold press of the olive. No chemical extractions are used in this process. By physical cold press, I literally mean the olive is pressed between two rollers and squeezed. Extra virgin is rated as such if it has no more than .8% acidity. Virgin oil is rated as such if it has less than .2% acidity.