Skin cells refer to the tiny, fluid-filled sacs (bladders) that are found in the skin. These bladders contain a protein called keratin, which provides strength and elasticity to the skin. Skin cells play an important role in providing protection against environmental factors such as bacteria, viruses, and other pathogens. They also help regulate body temperature by releasing sweat when we get too hot or absorb oils from our bodies to keep us moisturized. Additionally, skin cells are responsible for producing vitamin D when exposed to sunlight, which is essential for maintaining healthy bones and teeth.