Final answer:
Moisturizers are skin care products that restore hydration or moisture loss in the skin. They work by modifying the rate of water loss. Occlusives and humectants are the two main categories of active ingredients in moisturizers.
Step-by-step explanation:
Moisturizers are skin care products that help restore hydration or moisture loss in the skin. They work by modifying the rate of water loss. There are two main categories of active ingredients in moisturizers: occlusives and humectants. Occlusives form a coating on the surface of the skin, preventing moisture from escaping. Humectants absorb water, either from the air or from deeper layers of the skin, to moisturize the skin. In most practical applications, humectants are combined with occlusives for optimal moisturizing effect.