Aromatic olive oil is high in healthy monounsaturated fat and antioxidants. Its color varies from pale yellow to dark green, its flavor from mellow to bitter, from buttery to nutty, and from fruity to grassy, depending on where it’s from and how it’s processed. It has a moderate smoke point (the temperature at which it begins to burn) and so is best used for drizzling on vegetables, adding to salad dressings, and cooking foods at low to medium temperatures.
Of the various classes of olive oil, extra-virgin (made from the first cold-pressing of the olives, which best preserves their nutrients) is the most flavorful. It’s also the most expensive, so reserve it for dressings and drizzling on finished dishes, not cooking. The more information a producer puts on the label (kind of olives used, date of harvest, and so on), the more likely the oil is to be of a superior quality.