After the oil has been extracted, pomace remains: skins, pulp and stones. It still contains a little oil. This is dissolved out with solvents and then refined. To give it any olive taste at all, some virgin oil is blended in.
Olive pomace oil is a category of its own and may not be sold as olive oil. It must be clearly named on the label. It is used in catering and industry because of its low price.