Fats are esters formed from glycerol and three fatty acids, serving as energy storage molecules in biological systems and key components in food. They are hydrophobic lipids with varying chain lengths and saturation levels affecting physical properties like melting point. In food science, fats contribute to texture, flavor, and caloric content. Chemically, they undergo hydrolysis, oxidation, and transesterification. Common in animal and plant sources, they are insoluble in water due to nonpolar hydrocarbon chains but dissolve in organic solvents. Fats are essential for membrane structure, hormone production, and nutrient absorption of fat-soluble vitamins.