Linoleic acid (LA) and alpha-linolenic acid (ALA) are essential polyunsaturated fatty acids. LA is an omega-6 fatty acid with two cis double bonds, serving as precursor to arachidonic acid and eicosanoids. ALA is an omega-3 fatty acid with three cis double bonds, precursor to EPA and DHA. Both are critical for membrane fluidity, cardiovascular health, and inflammation modulation. Abundant in vegetable oils, nuts, and seeds. They cannot be synthesized by humans and must be obtained from diet. Chemically, they are long-chain carboxylic acids prone to oxidation due to unsaturation. In food science, they contribute to flavor stability and nutritional value of spices and oils.