Final answer:
The outermost layer of the skin is called the epidermis. It is a thin layer composed of keratin-filled cells and serves as a barrier to water and pathogens.
Step-by-step explanation:
The outermost layer of the skin is called the epidermis. The epidermis is the thin outer layer of the skin composed of keratin-filled cells. It acts as a barrier to water and pathogens, and it also contains melanocytes which produce melanin, giving the skin its color.