So let's begin by discussing function number one of the skin. And this is perhaps the most obvious function of the skin. So the skin creates a physical barrier that protects us from a wide range of harmful things. So recall that inside the epidermis of the skin, we have cells known as carotenesides. And these cells secrete a protein fiber known as keratin. And keratin not only gives the skin its strength, but it also protects our skin from water.