Sperm freezing, also known as sperm cryopreservation, is a process that preserves sperm cells at very low temperatures. This technique allows men to store their sperm for future use, which can be beneficial for those undergoing medical treatments, such as chemotherapy, that may affect fertility, or for individuals who wish to delay fatherhood. The process involves collecting a sperm sample, which is then mixed with a cryoprotectant to prevent damage during freezing. The sample is cooled gradually and stored in liquid nitrogen. When needed, the sperm can be thawed and used for assisted reproductive technologies, such as in vitro fertilization (IVF).