Moisturizer is a skincare product. Typically you'll want two kinds; one for your face and one for your body.
Face moisturizer is more expensive and is used in small amounts; many types even come with limited UV protection which is good for your skin. Every morning and every night after washing your face with a gentle cleanser, apply a small amount of face moisturizer to areas that feel dry (I.e bridge of nose, cheeks, forehead, etc.
You literally can't use too much of it and it makes you feel like a slime monster. (Jokes aside, I reccomend using this kind on your hands in the fall and winter, and anywhere else that feels dry)
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From @mysticmonster