UV-cut fabric, Sun Protection refers to a fabric's ability to protect the skin from UV radiation. Ultraviolet Protection Factor (UPF) indicates how much UV radiation (both UVB and UVA) a fabric allows to reach your skin. For example, a UPF 50 fabric blocks 98 percent of the sun's rays and allows two percent (1/50th) to penetrate, thus reducing your exposure risk significantly.
UV-Cut fabric is excellent UV resistance ability. It can block out the UVA/UVB rays that are harmful to humans, providing the best sun protection.