Sperm freezing, or sperm cryopreservation, is a method of preserving sperm for future use. It involves collecting sperm from a man, freezing it, and storing it in a sperm bank or fertility clinic. This procedure is often used by men undergoing medical treatments (like chemotherapy) that may affect fertility, or those who wish to delay fatherhood. The sperm can be stored for many years and later thawed for use in assisted reproductive techniques such as intrauterine insemination (IUI) or in vitro fertilization (IVF). Sperm freezing provides men with the option to preserve fertility for later use.