Male and female reproductive systems have evolved for different specialties, but for the same goal, to produce children. All of a woman's reproductive system is inside of the body, whereas much of a man's is outside of the body. The functional difference between male and female reproductive systems is that a woman's is designed to nurture a baby while it grows enough to survive in the world and a man's is a delivery system for sperm. The individual components of the systems also differ.

The reproductive system in women is entirely internal, with exit and entrance points at the vagina. Most noticeably, difference between male and female reproductive systems is the male genitalia on the outside of the body in comparison. The lower temperatures of the outside environment help keep sperm healthy, and prevent damage from the levels of heat found inside the body.

A woman has separate openings for urine and for menstruation and sexual intercourse, whereas the man only has one opening to let out urine and semen. Although the external portions of the vagina tend to become engorged with blood during sexual intercourse, a man's penis exhibits much more obvious engorgement. This allows him to use his penis for functional reasons and insert it into the vagina.

Both the male and female reproductive systems produce hormones, but the hormones differ. Women produce higher levels of female hormones like estrogen and men have more testosterone, for example. These hormones produce wide-ranging effects on the body, such as the development of secondary sexual characteristics like breasts or broad shoulders. Both the male and female reproductive systems start making lots of hormones at puberty.

Women have eggs already stored in the ovaries at birth, and the eggs simply release every month. Men, on the other hand, make new sperm regularly. The female reproductive system requires a monthly period to renew the lining of the womb, whereas the male system does not require regular maintenance in the same way.

Structurally, the female reproductive system is a storage and nurture area for an unborn baby. In addition, it is a space where the woman's eggs can mix with the male sperm to produce a new small human, which allows the woman to pass on some of her genes to the next generation, and the man to do the same. The male reproductive system does not contain any biological equipment which can support a new baby. Instead, it is a production and delivery system for sperm.