The Sievert (Sv) is the SI unit used to measure radiation dose equivalent, which quantifies the biological detriment of exposure to various types of radiation. It is derived by multiplying the absorbed dose, measured in gray (Gy), by a radiation weighting factor ($W_R$). This factor accounts for the differing biological impact of different radiation types, such as alpha, beta, and gamma radiation, allowing scientists to estimate the effective dose received by a biological system. Understanding this unit is crucial in health sciences and safety to set appropriate limits for environmental and medical radiation exposure.