Why it is called "EXTRA VIRGIN OLIVE OIL"......?

Extra virgin olive oil is the best olive oil. It has 1% or less acidity that goes through "cold pressed" procedure. In this process olives are crushed between huge, finely chiseled stones to produce a pulp, which is then layered on mats and hundred of tons of pressure are applied to extract the oil. These oils are unfiltered and refined. link: http://www.amazon.com/J-Leblanc-Extra-Virgin-Olive/dp/BOOOOKCKGC