Fats and oils are important types of lipids found in food and living organisms, and they play significant roles both chemically and physiologically. Chemically, fats and oils share many similar properties but differ primarily in their physical state at room temperature. Fats are typically solid or semi-solid, while oils are liquid. This difference arises mainly from their fatty acid composition and degree of saturation.

Fats and oils are esters formed from glycerol and three fatty acids, commonly called triglycerides. The fatty acids can vary in chain length and in the presence of double bonds. Saturated fatty acids have no double bonds and have straight chains, allowing them to pack tightly together, which results in a solid state at room temperature (fats). Unsaturated fatty acids contain one or more double bonds, which introduce kinks in the fatty acid chains, preventing tight packing and making them liquid at room temperature (oils). Monounsaturated fats contain one double bond, whereas polyunsaturated fats contain multiple double bonds.

One important chemical property of fats and