The human body's largest organ by surface area is the skin. The skin serves as a protective barrier, shielding the body from external elements, pathogens, and UV radiation. It plays a vital role in regulating body temperature, providing sensation, and enabling the synthesis of vitamin D when exposed to sunlight. The average adult's skin covers about 1.5 to 2 square meters and consists of multiple layers, including the epidermis, dermis, and subcutaneous tissue. Maintaining healthy skin is essential for overall well-being, as it reflects not only physical health but also emotional and psychological states.