Lactose is a disaccharide sugar composed of glucose and galactose units linked by a β(1→4) glycosidic bond. It is the primary carbohydrate found in milk and dairy products and serves as the main energy source for neonatal mammals. Lactose is commonly used as a sweetener, bulking agent, and excipient in pharmaceutical formulations. It is also utilized in the food industry for its emulsifying, browning, and flavor-enhancing properties.