Sunscreen works by protecting the skin from harmful ultraviolet (UV) radiation from the sun through two main mechanisms involving its active ingredients: UV absorbers (chemical filters) and UV reflectors (physical or mineral filters). UV absorbers are chemicals that absorb UV radiation and convert it into a small amount of harmless heat, preventing the UV rays from penetrating the skin. These chemicals typically absorb UVB and UVA rays, which are responsible for sunburn and skin damage leading to cancer. UV reflectors, usually mineral compounds like zinc oxide and titanium dioxide, sit on the skin surface and reflect and scatter UV rays away before they can penetrate the skin. Both types of ingredients often work together in sunscreens to provide broad- spectrum protection against different UV wavelengths. The ingredients are dispersed in a lotion, cream, or gel emulsion that helps them bind to the skin, maintain stability, and provide additional benefits like water resistance. Sunscreens labeled "broad spectrum" offer the best protection because they cover the whole range of UVA and UVB rays. In essence, sunscreen shields the skin by either absorbing or reflecting harmful sun rays, thus reducing risks of sunburn, skin aging, and skin cancer.