Skin.

The skin's anatomy consists of two major parts: the outer epidermis and the underlying dermis. The epidermis is composed of a particular kind of tissue called stratified squamous epithelium. Epithelium consists of cells that are packed together very tightly, a feature that is important to an organ that must cover and protect the rest of the body. It is called squamous, which comes from the Latin word for "scale," because its cells are flat and fit together like scales or tiles. The word “stratified” describes the dozens of layers of cells that are piled up to create the epidermis. These cells form four or sometimes five strata, each with their own characteristics and roles to perform.