The olive tree is indigenous to the Levant, in the Eastern Mediterranean, but is now grown and used extensively throughout the entire Mediterranean region. The first Spanish settlers introduced the olive tree to America, and in the late 1800's a professor at the University California invented a method for canning olives to boost the California olive industry. California is now known for its prized jumbo black olives. Blended oil, on the other hand, is based on the remaining oil which can be squeezed out of the already macerated olive. Blended oil is usually quite bitter and has to be refined and blended with other, blander oils, to mellow its flavors, hence its name.
Extra virgin is the most pure and flavorful oil, but also the most expensive.
While you might be tempted to choose a lesser quality oil for financial reasons, you may be surprised to find that a small amount of the more expensive oil goes a long way. The next time you reach for that innocuous looking olive on a relish tray or antipasto, take a moment to think of the importance it has had throughout time in Mediterranean, and currently American, cuisines. As stated earlier, the olive is amazing.