Phosphatidylcholine (PC) is the most abundant phospholipid in eukaryotic cell membranes, consisting of a glycerol backbone esterified at sn-1 and sn-2 positions with fatty acyl chains and at sn-3 with a phosphocholine headgroup. It serves structural roles in bilayers, acts as a lung surfactant component, and participates in lipid signaling via hydrolysis to DAG or LPC. In foods, PC is the primary component of lecithin from soy, egg, or sunflower, functioning as an emulsifier in chocolate, baked goods, and pharmaceuticals. Amphiphilic nature enables micelle and liposome formation. Dietary supplements support liver function and choline intake. Chemically variable due to acyl chain diversity (e.g., palmitoyl, oleoyl). Peer-reviewed studies confirm membrane fluidity modulation and bioavailability.