Olive oil is the best oil for humans as the easiest fat absorbed by human body. You should always use the highest quality of olive oil: extra-virgin (acidiy up to 0,80%) and organic/bio in order to protect yourself from bowel canser, Alzheimer's disease and many other disorders. Olive oil is pressed from olives (not extracted) and should smell of olives (not soil or any other stuff). Never buy olive oil with pepper or anything else inside, better do it at home yourself.
The best type of Olive Oil for cooking i.e light frying is probably 'pure' olive oil. Olive oil is actually graded according to the means of extraction, as well as the acidity levels it contains. The oil tastes better when the acidity is low. Extra virgin olive oil and virgin olive oil both come from the first pressing of the olives. Extra virgin olive oil has the lower acidity and so is generally regarded as the most flavoursome and the superior oil. Both these types of oil are considered to be appropriate for using in salad dressings or pasta dishes. Pure oil is extracted chemically from the paste which is left after the virgin oil has been pressed. This results in a taste which is less strong than virgin olive oil, but actually makes it better to cook with because it does not flavour the foods which it is being used to cook.