Moisturizers can be complicated—you have a lightweight moisturizer for the summer when your skin feels superoily, and a moisturizer for the winter when your skin is parched. You probably even bought those moisturizers because a friend told you one works wonders on dry skin or you read (possibly on this site) that your summer moisturizer won’t clog your pores. But do you really know how a good moisturizer is supposed to feel when you apply it? Should it take a while to soak in? And what exactly is a moisturizer?