Lactose is a natural sugar found in milk. It's obtained by evaporating whey, a byproduct of cheese production, then crystallizing and refining the remaining solids. Lactose is used as a sweetener, texturizer, and bulking agent in the food and beverage industry, found in products like confectionery, baked goods, dairy items, and infant formula. It also aids in browning and adds flavor in certain culinary applications.