What is the difference between a humectant, an emollient, and an occlusive?

These three ingredient types work together to keep skin hydrated but do very different jobs. Humectants like glycerin and hyaluronic acid draw water into the skin from the environment or deeper layers. Emollients like squalane and jojoba oil soften the surface and fill gaps between skin cells, improving texture and smoothness. Occlusives like shea butter and certain waxes sit on top of the skin and physically slow water from evaporating. A well-formulated moisturizer for dry or mature skin typically uses all three together, because relying on just one type – especially humectants alone in dry climates – often leaves skin still feeling tight by afternoon.