The placenta is a temporary organ that develops during pregnancy. It serves as an interface between the developing fetus and the mother's blood supply, providing nutrients and oxygen to the growing baby while also removing waste products from the baby's body. The placenta attaches itself to the wall of the uterus and is connected to the umbilical cord, which carries blood between the mother and fetus. After birth, the placenta is no longer needed and is expelled along with the afterbirth.