What are the differences between moisturizing and hydrating?

Hydration involves injecting moisture into the skin, directly replenishing water to skin cells. It not only moisturizes the surface layer of the skin but also penetrates deeply into the skin, binding closely with dehydrated cells, thereby improving dry skin conditions. Common hydrating products include toners, moisturizing waters, serums, and face masks. These products typically have a water-based texture and low molecular weight, allowing them to be quickly absorbed by the skin. Moisturizing, on the other hand, prevents water loss from the skin's surface and ensures the skin remains hydrated. Moisturizing products form a protective layer on the skin's surface, locking in moisture and preventing evaporation. Common moisturizing products include creams and lotions, which usually contain oils or moisturizing factors that enhance the skin's ability to retain water.