Duchess we had a pretty thorough discussion on the differences between the olive oils not that long ago... Here's a link to the thread.

Olive Oil Q

Just the basics:

Pure Olive Oil:
A general purpose oil, not really for the table but the food industry. It is solvent-extracted from olive pulp, skins, and pits; then refined. It is light and bland. Pure refers to the fact that no non-olive oils are mixed in.

Extra-Virgin Olive Oil:
Any olive oil that is less than 1% acidity, produced by the first pressing of the olive fruit through the cold pressing process. Most olive oils today are extra virgin in name only, meeting only the minimum requirement.

Premium Select Extra-Virgin Olive Oil
This is the top grade of olive oil. With a lower rate of acidity than 1%. Some as low as .225%. This level of quality can only be achieve one way - through hand harvesting and pressing within 24 hours.

Nat