Cryopreservation is a process used to preserve cells, tissues, or even whole organisms by cooling them to very low temperatures. This technique halts all biological activity, including the processes that lead to cell death. It is commonly used in fields like medicine, biology, and agriculture to store valuable genetic material, such as sperm, eggs, and embryos. The most common method of cryopreservation involves using liquid nitrogen, which can reach temperatures as low as -196 degrees Celsius. This extreme cold prevents ice crystal formation, which can damage cells. Cryopreservation is essential for assisted reproductive technologies and the conservation of endangered species.