Detailed answer

Moisturizers are usually cream or lotion-based products that are designed to prevent moisture loss from the skin and provide a protective barrier. They contain a combination of occlusive, humectant, and emollient ingredients to nourish and hydrate the skin. On the other hand, hydrating serums are lightweight, water-based products with a high concentration of humectant ingredients. They are formulated to deeply hydrate and plump the skin by attracting and retaining moisture. While both moisturizers and hydrating serums help to hydrate the skin, moisturizers are generally more occlusive and work on the surface, while hydrating serums penetrate deeper into the skin layers to provide intense hydration.