Cosmetic ingredients are the various substances used in beauty and personal care products to enhance appearance or improve skin health. These ingredients can include natural elements like plant extracts and essential oils, as well as synthetic compounds designed for specific functions, such as moisturizing or sun protection. Common categories of cosmetic ingredients include emollients, which soften and smooth the skin, and preservatives, which prevent product spoilage. Other ingredients, like fragrances and colorants, are added for sensory appeal. Understanding these components helps consumers make informed choices about the products they use on their skin.