The epididymis is a coiled tube located at the back of each testis. It plays a crucial role in the male reproductive system by storing and maturing sperm cells produced in the testes. The epididymis allows sperm to gain motility and the ability to fertilize an egg. This structure is divided into three parts: the head, body, and tail. Sperm travel from the testes to the epididymis, where they can remain for several weeks. Once mature, sperm are transported from the epididymis to the vas deferens during ejaculation, playing a key role in reproduction.