Fats and oils are members of the same class of chemical compounds, the triglycerides. They differ from each other only in their melting points: oils are liquid at room temperature, fats solid. Rather than use the technical triglyceride to denote these compounds, I’ll use fats as the generic term. Oils are liquid fats. These are invaluable ingredients in cooking. Their clingy viscosity provides a moist, rich quality to many foods, and their high boiling point makes them an ideal cooking medium for the production of intense browning-reaction flavors.