From the latin vivipărus, viviparous is an adjective which allows to allude to the female who gives birth to her cubs to an already fairly developed State. In other words, a viviparous animal is that the embryo develops in the womb of the mother, in a special structure to receive the food and oxygen necessary to develop until birth.
The viviparisme can take many forms. Some viviparous animals have no placenta, such as marsupials. In this case, the fetus is put down to a premature State, reason why it should continue its development in an outer envelope. The placental viviparisme, in turn, is the most common in mammals.
Plants may also be viviparous. This is the case of plants whose seeds germinate before separating from the mother plant.
There are viviparous animals, the oviparous and the ovoviviparous. The oviparous reproduce by laying eggs in an external medium. The fetus completes its development in this same egg until hatching.
Concerning the ovoviviparous, are animals which contain the eggs in its interior until hatching, which can take place either immediately after the egg is laid, or at another time.
Certain characteristics are common to all three forms of reproduction. For example, for the oviparisme and the ovoviviparisme, the embryo nutrition depends on reserves of the egg. In addition, the ovoviviparous and viviparous have in common the fact of the development of the embryo inside the mother's body.