Frying oil is any fat used as the cooking medium for shallow frying, deep frying, sautéing, or stir-frying. The main factor in choosing one is smoke point: neutral, high-smoke-point oils such as peanut, canola, sunflower, and vegetable oil are the default for deep frying and stir-frying because they hold up under sustained high heat without breaking down or adding strong flavor, while more flavorful, lower-smoke-point oils such as extra-virgin olive oil are better suited to shallow frying and sautéing, where their taste becomes part of the dish. Unrefined oils carry more of their source's natural flavor and aroma; refined oils are processed to be more neutral and heat-stable. Common sources include soybean, peanut, sunflower, canola, olive, and palm.